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Received for publication July 17, 1957. Paper NS 235 from the Department of Veterinary Science, University of Wisconsin, Madison, published with the approval of the director of the Wisconsin Agricultural Experiment Station. * On leave from the Central Institute of Hygiene, Zagreb, Yugoslavia. Many of the blood samples from wild birds were collected by Drs. L. E. Starr and R. L. Watson, Georgia Department of Public Health. Dr. Watson is now Public Health Veterinarian, U. S. Public Health Service, Baltimore, Maryland.

A description is given of a simple method of determining the sensitivity of bacteria to sulphonamides by means of impregnated blotting-paper disks applied to nutrient agar prepared from broth freed from sulphonamide antagonists by incubation with lysed horse red blood cells.With organisms sensitive to the selected sulphonamide, a zone of inhibition of growth will occur, the diameter of which is related to the concentration of the sulphonamide necessary to inhibit growth. Sensitivity to several sulphonamides can be determined simultaneously.The impregnated disks can be stored without loss of potency.

1) The microbiological niacin assay was simplified by using the niacin discs on the niacin-free plate media inoculated Proteus. The relationship between niacin contents in the discs and diameter of the colonies is as follows; D=5 x-2.5 D=Diameter of colony, x=log2N (N=niacin).The measuring range is 8 mcg/ml-64 mcg/ml.2) The extract from Mycobacterium Tuberculosis had niacin enough to make the colony of Proteus on the niacin-free media. but atypical A.F.B. did not.

Electrophoretic patterns of human blood serum protein were studied in parasitic diseases including 19 cases of clonlrchiasis, 29 cases of clonorchiasis and other helminthiasis and 22 cases of healthy controls in Kim-hae area. The same study was made on 32 cases of ascariasis, 56 cases of trichocephaliasis, 80 cases of ascariasis and trichocephaliasis, 9 cases of amebiasis and 44 cases of healthy controls in the Seoul Juvenile Center. The total serum protein was performed by Folin method and the serum protein fraction test by Durrum's paper electrophoretic method. The results were as follows: 1. In the case of clonolrchiasis, the total serum protein, albumin fraction and A/G ratio decreased and alpha(1) globulin fraction increased twice as much as in the case of healthy controls. 2. In the case of clonorchiasis and other helminthiasis, alpha(1) globulin fractions increased. 3. In the case of ascariasis, albumin fractions increased but alpha(1) globulin fractions decreased. 4. In the case of ascariasis and trichocephaliasis, alpha(2) and beta globulin fractions decreased. 5. In the case of amebiasis, alpha(1) globulin decresed.

Microbiological assay of individual antibiotics in mixtures of antibiotics depends on the use of selective inactivation and/or of test bacteria with differential susceptibility. Controlled experiments revealed that streptomycin in concentrations of 20 and 40 μg/ml did not influence a disk diffusion assay of penicillin with Sarcina lutea (ATCC 9341) as the test organism. In the case of penicillin concentrations less than or equal to 1 IU/ml, addition of 80 μg of streptomycin per ml influenced the penicillin assay significantly. Clinical use of streptomycin resulting in levels above 40 μg/ml usually did not occur; therefore penicillin could be assayed as though streptomycin were not present. We observed additionally that S. lutea was unable to grow on agar plates prepared with semicarbazide hydrochloride.

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The Editor has asked me for a brief note to explain how a number of papers by my husband came to be published in this Journal during the two years following his death.

1) Unidimensional and two dimensional paper choromatogram were prepared of 10 kinds of parastic helminths. 2) Fourteen amino acids were identified from the acid hydrolysed tissue proteins of A. lumbricoides(cuticle and musculature), A. galli, F. hepatica, E. pancreaticum, P. cervi, T. solium, and M. expansa. They were glycine, alanine, serine, threonine, methione, valine, leucine, aspartic acid, lysine, arginine, tyrosine, proline and histidine. In hydrolysates of A. lumbricoides(female genital organ) and C. sinensis, 13 amino acids were recovered. Twelve amino acid from A. lumbricoides(intestinal tract), 9 from P. westermani, and 6 from H. nana were also identified in the tissue hydrolysates.

After the growth of Paecilomyces persicinus P-10 in a glucose-peptone medium, filtrates were collected and analyzed for antibiotic antivity. Activities against Salmonella gallinarum ATCC 3030 and Alcaligenes faecalis ATCC 8750 (penicillin N-resistant strain) were obtained. Part of the former activity was readily inactivated by penicillinase. The fraction active against A. faecalis was isolated by passage through Amberlite XAD-2 and Amberlite IRA-68. The powder eventually obtained was subjected to paper chromatography followed by bioautography, and the activity obtained corresponded to that of a sample of cephalosporin C. Thin-layer chromatography was also employed to verify the presence of cephalosporin C in the P-10 powder. The active solids were further purified by means of paper chromatography in a solvent system consisting of n -butanol-acetic acid-water (60:15:25, vol/vol). The material obtained from this procedure yielded an infrared absorption spectrum identical to that of cephalosporin C. Similarly, the ultraviolet absorption of the purified preparation coincided with that of cephalosporin C. Exposure of the purified solids to cephalosporinase resulted in rapid inactivation of the antibiotic. In addition to penicillin N and cephalosporin C, filtrates of P. persicinus P-10 also contained deacetylcephalosporin C, deacetoxycephalosporin C, and cephalosporin P.

A comparison of the proteins of ‘R’ and ‘T’ strains of mosquito iridescent virus (M1V) was made using PAGE and amino acid analysis. The banding patterns of RMIV and TM1V were similar, each showing 9 proteins. None of the proteins reacted with Schiff’s reagent. When the proteins of RMIV and TMIV were S-carboxymethylated, PAGE showed only 4 proteins for both strains compared with the 9 bands detected in control preparations. Amino acid analyses and tryptic peptide analyses indicated that the proteins of the two strains were very similar.

A capsular polysaccharide was isolated from a strain of Clostridium perfringens Hobbs 10 type A by cold-water extraction of whole, heavily encapsulated cells. The water-soluble polymer was isolated by alcohol precipitation and purified by treatment with chloroform-butanol, cetytrimethylammonium bromide, and column gel permeation chromatography by using Bio-Gel A-5m agarose. The formation of a single precipitin line, when the isolated polysaccharide was reacted with its homologous antisera by double diffusion in gel, was considered a criterion of immunochemical purity. The purified polymer appeared as a single peak when eluted from diethylaminoethyl-Sephadex with a linear gradient of NaCl. The polysaccharide was composed of glucose, galactose, galactosamine, and iduronic acid in a molar ratio of 4.1:5.1.7:1, respectively. These constituents accounted for 83% of the dry weight. The polysaccharide appeared to have a molecular weight of 40,000 and exhibited aggregation up to 120,000. A trace of peptide material could not be removed during purification.

It has been assumed in the past that the lipid moieties of endotoxic lipopolysaccharides are quite similar if not identical. This has been tested in the reported work here, where the chemical composition and biological activities of the glycolipids of two heptoseless Re mutants, Salmonella minnesota R595 and Salmonella typhimurium SL1102, have been studied and compared. The two glycolipids, extracted with chloroform-methanol (4:1), showed identical thin-layer chromatographic patterns. The molar ratios for hexosamine, fatty acids, phosphorus, 2-keto-3-deoxyoctonate, total amines, and total nitrogen of the purified glycolipids were in the same range, but small differences could be established. Both glycolipids contained the same major fatty acids, i.e., lauric, myristic, palmitic, and 3-hydroxymyristic acids, in similar but not identical ratios. On paper electrophoresis, the acid hydrolysates of the two glycolipids showed analogous components. In the determination of molecular weight, whereas S. minnesota R595 glycolipid did not show concentration dependence, the molecular weight measured for S. typhimurium SL1102 increased with its concentration. The molecular weight of the fully endotoxic R595 glycolipid has been found to be 17,000 ± 1,500. Both glycolipids showed similar activities in the Shwartzman skin reaction, Limulus -lysate clotting assay, mouse lethality, and enhancement of nonspecific resistance, but the R595 preparation appeared to be more active on a weight basis in some parameters than SL1102. Using passive hemagglutination, we observed cross-reactivity between the glycolipids. In the gel-diffusion test, they revealed clear identity. The antiserum against S. minnesota R595 neutralized the Shwartzman skin reactivity not only of R595 but also of SL1102 glycolipid. These results confirm that there are identical immunodeterminant group(s) in the two glycolipids. On the other hand, chemical analytical data for two glycolipids showed only similarities, indicating that although both glycolipids are of comparable chemical nature, differences between them exist.

Lysates of human peripheral blood leukocytes that contained acid hydrolases solubilized 65% of the total radioactivity from 14C-labeled Staphylococcus albus after incubation for 18 hr at 37 C in acetate buffer, pH 5. Under similar conditions only 28%, 5.0%, and 2.5% of the total radioactivity was released from Staphylococcus aureus, group A Streptococcus, and A-variant streptococci, respectively. While the solubilization of radioactivity from S. albus was accompanied by the release of most of the glucosamine and by extensive cellular breakdown, the release of glucosamine and cellular breakdown of S. aureus were more moderate. However, no substantial degradation of streptococci was evident. Treatment with trypsin and lysozyme before addition of leukocyte lysates did not increase the solubilization and cellular breakdown of streptococci. However, such treatment greatly enhanced lysis of S. albus. Solubilization of radioactivity from staphylococci was accompanied by release of normal constituents of bacterial cell walls, e.g., glucosamine, muramic acid, alanine, lysine, glutamic acid, and ribitol (as revealed by paper chromatography). Under similar conditions, only alanine and a small portion of glucosamine were released from streptococci after treatment with leukocyte lysates. The use of radiochromatography and electron microscopy for study of the interaction of leukocyte enzymes with bacteria may contribute to our understanding of the interrelationship of leukocytes and bacteria.

Cold 10% trichloroacetic acid was used to extract antigens from purified cell walls of Streptococcus mutans BHT. Column chromatography on Biogel P-100 resolved two serologically reactive fractions (B and C). These fractions were ascertained to be relatively pure by recycling on Biogel P-100, Ouchterlony double-diffusion analysis, and immunoelectrophoresis. Fractions B and C demonstrated bands of absolute homology by double-diffusion but different mobilities by immunoelectrophoresis. Chemical analysis indicated that fraction B is a polysaccharide composed principally of rhamnose and galactose, with smaller amounts of glucose and glucosamine. Small quantities of glycerol and phosphorus also were found. Fraction C was composed mainly of galactose, glycerol, and phosphorus. Alkaline hydrolysis of this fraction yielded products typically released by the degradation of a glycerol teichoic acid, such as glycerol monophosphate, glycerol diphosphate, inorganic phosphorus, and several glycosyl glycerol phosphates. Diglycerol triphosphate was not detected. Side-group analysis revealed that glycerol was substituted by mono- and trigalactosyl moieties. Fraction C was deduced to contain 25 glycerol phosphate units per polymer length. Hapten inhibition studies revealed a β-galactoside as the probable hapten on this antigen. The BHT teichoic acid reacted strongly with FA-1 antiserum. It showed bands of homology with both BHT and FA-1 crude acid extracts upon double-diffusion, using antisera to either strain. The BHT teichoic acid also displayed immunoelectrophoretic behavior identical to one of the mobile FA-1 cell wall antigens, again using either serum to develop precipitin bands. It is concluded this antigen may possess a serotype-specific determinant for S. mutans serotype b .

Suitable mesenteric glands were selected from virus hogs, the glands carefully dissected out of mesentery, covered with 10 times their weight of absolute alcohol, and placed at 37 C. over night. The alcohol was then decanted off, the glands thoroughly ground with sterile sand, and the alcohol again added to the ground glands. The preparation was then placed at 37 C. for 8 days and thoroughly shaken each day. At the end of this period the preparation was filtered through an ordinary, white, folded filter paper. The filtrate, which measured 670 c.c, was evaporated by the aid of an electric fan to a somewhat pasty, deeply yellow mass. This mass was partly dissolved in 225 c.c. of ether and set aside to sediment. The ether was decanted from the sediment and allowed to evaporate to a volume of 15 c.c. To this 15 c.c. were added 75 c.c. (5 times its volume) of acetone. A heavy, flocculent precipitate immediately formed, which was allowed to settle, whereupon the supernatant liquid was decanted. Twenty-five cubic centimeters of methylic alcohol were added to the precipitate. The methylic alcohol dissolved a portion of the precipitate, leaving, however, a deeply yellow, sticky mass undissolved. After sedimentation the methylic alcohol, decanted and diluted 1:10 with normal salt solution (1.5 c.c), was used as antigen in amounts varying from 0.01 c.c. to 0.03 c.c. with, in each case, 0.05 c.c. immune serum, 0.045 c.c. complement, 0.1 c.c. hemolysin, and 0.5 c.c. red blood corpuscles. The antigen, immune serum, and complement were mixed and placed at 37 C. for 1 hour, whereupon the hemolysin and corpuscles were added and the whole placed at 37 C. for 2 hours. Complete hemolysis followed in every case. The test for complement absorption was negative. This test was repeated with 10 times the dose of antigen used in the first test, and the result was again negative.

The method here described is an outgrowth of the technic for the isolation of single micro-organisms as described in previous papers.1 The new feature makes possible not only the segregation of one or more micro-organisms but the injection of them as well as of measured doses of fluids into the protoplasm or vacuoles of living cells. In order to accomplish this, pipettes have to be constructed of such a fineness as to minimize the injury to the cells injected and of sufficient rigidity to pierce the cell wall. Further, an injection force has to be employed sufficient to overcome cell pressure, capillarity, and any obstruction in the pipette. The first requirement was met by modifying the method of drawing pipettes, and the second by the use of the expansion of mercury as a source of power for injection. Each phase of the method and each part of the apparatus will be described in detail, and, for the most part, in the order that one would follow in carrying out the process. The pipette holder {ph, Fig. 4) is the same as that described for the isolation method. It consists essentially of an attachment to the stage of the microscope which holds the pipette, and by means of screws allows an up-and-down and a lateral movement of the pipette (sv and si, Fig. 4). A double pipette holder, which is described below, may be used in place of the simpler form. Any mechanical stage may be employed which allows a considerable range in both directions. The glass box is prepared as for the isolation method. Two convenient forms have been used, the smaller 60 mm. long by 25 mm. broad by 16 mm. high and a larger one 70 mm. long by 36 mm. wide by 16 mm. high. Water is kept in the bottom of the box and, further to insure moisture, the sides are lined with wet filter paper. A number 2 cover-glass

In the course of a series of experiments carried on by the Massachusetts State Board of Health it became necessary to devise a method for separating and determining quantitatively small amounts of copper in water; such a method has been worked out and is published in detail in the "Standard Methods of Water Analysis" of the Laboratory Section of this Association.1 It is the purpose of this short paper to give a brief outline of the method, together with some experimental results, and to call attention to certain statements that have appeared in print regarding the total disappearance of the copper in a few hours when applied to a water supply, and the impossibility of detecting it in the water by chemical tests. The chemical test in general use for detecting copper in solution in small quantities is that mentioned by Moore and Kellerman in Bulletin 64 of the Bureau of Plaftt Industry, and consists of adding potassium ferrocyanide to the solution to be tested, acidified by acetic acid. The sensitiveness of this test is shown by the following figures.

The experiments reported in this paper were undertaken with a view to arriving at definite conclusions in reference to some stages in the production of sanitary milk, or so-called "certified milk." The results shall be discussed under four heads, with an added fifth part for a short criticism of dairy score cards. The four experimental parts are: i. A study of the bacterial content of separator milk and cream. 2. Comparative tests of the value of narrow top pails with and without strainers.

The use of collodion sacs and parchment membranes for the study of the longevity of B. typhosus in natural waters and sewage was introduced by Jordan, Russell, and Zeit1 in 1904 in their work on the Chicago Drainage Canal case. The particular advantages of this technic over the methods employed up to that time are that the typhoid bacilli are confined within comparatively narrow limits and can thus be recovered more easily than otherwise, and that at the same time the organisms thus confined are exposed to conditions as nearly as possible like those found in nature, since there is quite a free interchange of diffusible substances through the permeable walls of the sacs. In 1905-6 Russell and Fuller2 used similar containers in a more extended study of the vitality of the typhoid bacillus in surface waters and sewage. Recently the entire reliability of the results obtained by the use of collodion and parchment containers has been questioned on the ground that it is not possible to prepare either collodion or parchment sacs through which the typhoid organism will not pass in a few hours, and that the figures reported in the above-mentioned experiment are unreliable because they do not take into account the escape of a certain number of the typhoid bacilli through the walls of the sacs during their exposure in water and sewage. Johnson,3 in a paper before the New England Waterworks Association, in 1905 first called attention to this, and cited certain experiments performed by him which apparently showed that B. coli could pass readily through parchment sacs, which retained perfectly their integrity as far as their dializing properties were concerned throughout the experiment. He showed that these organisms could be recovered from sterilized water in which parchment sacs filled with

Gins1 was perhaps the first to employ India ink for outlining bacterial capsules and organisms that are stained with difficulty. Since his paper there have been several articles about the use of India ink for similar purposes, notably those by Rulison,2 Gozony3 and Baker.4 However, in none of these reports is there a consideration of the action of diluents used in the suspension of the organisms that influence the size of the capsular zone. Such factors, we have found, are of considerable importance in obtaining the maximum zone about encapsulated bacteria in India ink. It is well known that most of the direct and indirect methods for visualizing bacterial capsules, described in text books and in the current literature are of dubious value for the demonstration of capsules of hemolytic streptococci. Furthermore the employment of India ink for such purposes without regard to the necessary details give poor results. When properly used, India ink is of great value for the demonstration of bacterial capsules. The improved India ink technique is given in detail and also a new method for the use of azo blue instead of India ink.

Under well-established culture conditions, Pseudomonas reptilivora produced several antibiotics that have been purified by solvent extraction, chromatography in Sephadex G-25, electrophoresis, and paper chromatography in different solvent systems. Activity has been monitored at the different steps of isolation and purification by measurement of the inhibition of the growth of Staphylococcus aureus by the cylinder-plate method, as well as by bioautography of chromatograms and electropherograms. Three antibiotics have been isolated and named A, B 1 , and B 2 . The B 1 and B 2 activities were studied in greater detail than A. The B 1 substance was crystallized, and its chemical properties were found to coincide with those of YC 73 or fluopsin C described by Egawa et al. and Itoh et al., respectively.

The most widely used method for routine antibiotic susceptibility testing of clinical isolates of bacteria is the paper-disc method. This has the advantage of simplicity, but to obtain reliable results considerable care is required both in the standardization of the procedure and in the interpretation of the zones of inhibition. A new susceptibility test method is described in this report which retains the simplicity of the paper-disc method but which enables organisms to be tested directly for susceptibility to known concentrations of antibiotic in agar. Organisms may be tested against a single concentration of antibiotic or, alternatively, a range of concentrations may be used to determine the minimal inhibitory concentration. The method utilizes stable pre-prepared materials and is not appreciably more time consuming than the conventional disc method.

Liquid feces were filtered directly by means of fine filter paper; semisolid or solid feces were mixed with 0.9% salt solution so as to obtain as concentrated an extract as possible and then filtered through a Buchner filter. If the extract was acid to litmus paper, it was neutralized with dilute sodium hydrate solution; if alkaline, by means of dilute hydrochloric acid. Chloroform was added to restrain bacterial growth. Clarification of the extract was secured by rapid centrifugation. The precipitin tests were made in small, clear glass tubes, about 0.5 cm. in diameter; a small quantity of extract was placed in the tube and about 0.1 cm. of antihuman rabbit serum introduced at the bottom by means of a capillary pipet in such manner as to get a precise line of contact between the two fluids. The tubes were kept at room temperature and the results read after one hour. In most of the positive reactions there formed rather promptly a well defined precipitate in form of a grayish layer at the junction of the extract and the serum. As a rule the antihuman serum was 12,000 in titer, that is, it would give a precipitate within 20 minutes at room temperature with dilution of human blood 1: 12,000 in salt solution. The specimens of feces from patients under treatment were obtained from the service of Dr. B. W. Sippy in the Presbyterian Hospital and from the private practice of Dr. Milton M. Portis; most of the specimens were obtained from the latter source. The specimens from cases of pernicious anemia came from patients in various hospitals. The specimens from normal persons were mostly from young men in military training, the others from medical students.

The enzyme neuraminidase (EC 3.2.1.18) was found to be strongly active in different types of Streptococcus sanguis and S. viridans , and, in addition, the occurrence of the enzyme acylneuraminate pyruvate lyase (EC 4.1.3.3) was described in S. viridans . The enzyme-active bacteria strains were isolated from blood cultures of patients with septicemia. Whereas S. sanguis lost its strong neuraminidase activity after some weeks, S. viridans retained its enzyme activity for a long time in culture. Immunoelectrophoretic studies of the blood cultures of patients with streptococcal infections showed the loss of neuraminic acid in most glycoproteins of the serum, proving the in vivo action of neuraminidase. The pathogenic role of neuraminidase is discussed in streptococcal septicemia from the viewpoint of present knowledge.

In a β-lactamase-inducible strain of Staphylococcus aureus , the enzyme appears spontaneously in the absence of added inducer during lag and early log phases of growth and then declines rapidly to low levels. The endogenous inducer responsible for appearance of the enzyme has been isolated and purified and characterized as a peptidoglycan, containing muramic acid, glucosamine, glutamic acid, alanine, lysine, and glycine. The inducing compound could be isolated from the cells only during the lag and early log phases and from no other later periods. The data obtained are consistent with the thesis advanced earlier from this laboratory that β-lactamase serves a cellular function in the producing cell more important and beyond its capability of hydrolyzing certain penicillins to the antibiotically inactive penicilloic acids.

The means by which coxsackievirus type A9 (CA9) is inactivated by proteolytic enzymes was investigated. After reaction of 14 C-leucine-labeled CA9 with Pronase, free leucine was liberated as measured by radiochromatography. Treatment of 14 C-leucine-labeled CA9 with trypsin or proteolytic filtrates of Pseudomonas aeruginosa caused the release of a variety of labeled substances. The extent of viral ribonucleic acid (RNA) release after exposure of CA9 to Pronase was determined by RNA infectivity tests or trichloroacetic acid solubility tests. Infective viral RNA was found not to be consistently released by reaction of CA9 with Pronase, but further treatment with 1% sodium dodecyl sulfate at pH 7.0 promoted viral RNA release. Sodium dodecyl sulfate treatment of CA9 that had not been reacted with Pronase did not inactivate virus or cause viral RNA release. Reaction of Pronase with 32 P-labeled CA9 resulted in the liberation of virus components soluble in cold trichloroacetic acid, whereas untreated CA9 or CA9 reacted with ribonuclease were precipitated by cold trichloroacetic acid. These results demonstrate that the primary means by which protease-sensitive enteroviruses are inactivated is by degradation of the virus capsid, with subsequent release of viral RNA.

At a recent meeting of the American Public Health iVssociation, B. R. Rickards1 reported the result of an investigation of the methods of disinfection employed in the larger cities of the United States. He had sent a circular letter to every city of over 100,000 and received replies from 29 cities. The methods employed in these cities were as follows: Formaldehyde generators 9 Generators alone 5 Combined with other methods 4 Permanganate-formalin method 12 Permanganate method alone 9 Combined with other methods 3 Solidified formaldehyde 9 (proprietary articles sold under various names) Solidified formaldehyde alone 4 Combined with other methods 5 Formalin sheet spraying method 4 Sheet spraying alone 2 Combined with other methods 2

An investigation was carried out into the bacteriological performance of three air-conditioning plants in a hospital ward. Two of these plants had the facility for recirculating part of the ward air.An equation has been derived comparing the concentration of bacteria which would be expected to be given off by the humidifiers in the ventilation system, with the concentration of bacteria in the recirculatory tank. The bacterial particles given off by these humidifiers were of nuclei droplet size, and were found to penetrate the filters used with a fair degree of ease. Although the number of bacteria in the humidifier water remained insignificant with a constant overflow of water into the recirculatory tank, on one occasion a build-up of bacteria was demonstrated when the overflow ceased. For hospital use humidifiers of a non-recirculatory type should be used.The concentration of bacteria on the surface of the recirculatory ducts was assessed, as also were those on the surface of the supply ducts under full fresh air and recirculation. The concentration of bacteria in the supply ducts was low and the use of terminal filters was not merited, although care should be taken to prevent the build-up of bacteria in inlet grills and diffusers. The bacterial concentration in the exhaust ducts was found to be quite high. It was therefore thought that in critical areas, where the ventilation plant may be shut off, the use of some device to prevent reversed air flow may be necessary.The count of various types of micro-organisms in the fresh air and two-thirds recirculated air are given along with their size distribution. The results of the effect of filtration on the concentration of bacterial particles throughout the air-conditioning plant is given under full fresh air and recirculation. These concentrations appear quite satisfactory. It was found that one set of filters had been overgrown by mould because of free water being brought over from the humidifier. Measures have been suggested to overcome this. When primary or prefinal filtration was approximately 90% efficient to Aloxite 50 (B.S. 2831 Test Dust no. 2) it was demonstrated that a fair approximation to the final filtration figure could be obtained by reference to the quoted efficiency of the final filter to Aloxite 50. After similar primary filtration it was demonstrated that the final filtration of filters against recirculated and fresh air was approximately the same. Owing to the higher number ofStaph. aureusin recirculated air, higher efficiency filtration may be required.Standards of filtration efficiency for critical and non-critical zones are suggested.

Separation of homogenates of human polymorphonuclear leukocytes (PMN) into different fractions by sedimentation in centrifugal fields that ranged from 126 × g to 50,000 × g resulted in a differential distribution of the lysosomal enzymes. Peroxidase, lysozyme, beta-glucuronidase, and acid phosphatase activity were separated from each other. This demonstrates that the lysosomes of human PMN comprise at least three and possibly four physically and chemically different cytoplasmic particles. Proteins which are more cationic than lysozyme and which may be analogous to cationic lysosomal protein of rabbit PMN were associated with lysozyme and beta-glucuronidase rich granules. Antibacterial activity was present in four of the five cell fractions which this work produced. These results are significant because they differ from those obtained with rabbits and because they directly influence future experimental design and interpretation, in attempts to analyze antibacterial, scavenging, and inflammatory capacities of human PMN. Since lysosomes differ physically, biochemically, and morphologically, they may well differ with respect to their function in the PMN.

reduce that difficulty to a minimum and at the same time contribute to a proper understanding of the test itself. After trying mercury as a seal in the Smith fermentation tube, which fails on account of its germicidal action, and sand, which works but is troublesome, it was decided to combine the principle of the constricted tube (Hall,1 1915) with that of the fermentation tube so as to use a mechanical seal.

The value of sunlight in human dwellings as an aid to healthy living has been recognized from involuntary human experience from time immemorial. The actual germicidal effect of light has been a subject of study ever since 1877, when Downes and Blunt,2 in a classic series of experiments, demonstrated that light inhibited bacterial growth, and that the blue end of the solar spectrum was the more efficient for this purpose. A host of investigators studied the phenomenon in the eighties and nineties, some turning to the electric arc as a source of bacterial light, and a group, headed by Finsen, made the first application of the phenomenon in the treatment of certain forms of tuberculosis with the Finsen lamp. It was not until within a few years, however, that the invention of the quartz tube mercury arc lamp, and an awakened interest in water disinfection gave impetus to the study of water disinfection with ultra-violet light.

It has been known definitely since the time of Koch that certain essential oils have considerable disinfectant value. It has been assumed since his time also that substances which have disinfectant value when in watery solution are largely rendered inactive by solution in oil. This assumption arose as a wide generalization from what was actually observed by Koch in only one case, namely, that of phenol in vegetable oils, such as olive oil or cotton seed oil. In this case the validity of the observation is undoubted, but there have been a very few practitioners who have believed that in spite of the test tube indications the best way to apply phenol as a wound disinfectant is in solution in vegetable oil. The recent application by Dakin7 and his associates, of solutions of a water-insoluble oil-soluble substance (dichloramin-T) to the treatment of wounds indicates that from the practical point of view the question of the usefulness of disinfectants in oil is by no means closed. As a consequence of these general considerations, I undertook to study these questions anew. The recognized methods of determining quantitatively the antiseptic value of substances presuppose water solubility. The immiscibility of water and oil prevents the use of broth culture (or the suspension of bacteria in salt solution) in the testing of an oily substance, or of material which has been in contact with an oil. It is doubtless for this reason the physical difficulty of testing by standard methods that the many new antiseptic oils and oil-soluble antiseptics are accepted solely on the basis of clinical experience and not on that of known germicidal power. The value of such oils has not up to the present been expressed in terms of a known standard, comparable to the "phenol coefficient" of water-soluble antiseptics. Face to face with the necessity of deciding accurately the antiseptic power of a large number of oils the need for a preliminary investiga

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The type-specific main (TM) antigen was extracted from the leptospiral cells of strain Kyoto of the Hebdomadis group by 90% phenol and was purified mainly by ethanol precipitation. The TM antigen was specific, forming one precipitin band by immunodiffusion and reacting by complement fixation test with anti-strain Kyoto serum; so far as has been tested, it does not appear to react with antisera of other serotypes. The sedimentation velocity of the TM antigen was 216 S . Morphologically the TM antigen was filamentous in shape with a uniform width of 25 to 30 nm and various lengths from 50 nm to 1 μm. The infrared absorption pattern of the TM antigen generally resembled that of gram-negative bacterial endotoxin, and this fact suggests that the antigen is composed mainly of lipopolysaccharides. Galactose, rhamnose, xylose, arabinose, glucosamine, 13 kinds of acidic and neutral amino acids, lipids, and phosphorus were found in the TM antigen.

In any method of standardisation it is necessary that the test shall be carried out at a constant temperature, as the disinfection process has a high temperature coefficient. For any method to be of general application, it is also necessary that the temperature selected shall be adhered to in all determinations, since the temperature coefficient of disinfection varies for different disinfectants. The temperature adopted was 20° C.In the case of vegetative organisms a disinfectant varies in efficiency as much as ten times according to the organism against which it is tested. Some disinfectants are more efficient against one vegetative species of bacteria, others against another.The presence of 10% blood serum reduces the efficiency of 1% phenol about 12%. The effect upon emulsified disinfectants is somewhat greater. With mercuric chloride the reduction was much greater, a 0·5% solution being reduced to from 0·6 to 0·06 of its original value as the concentration of serum was increased from 5 to 30%.

The following investigation was undertaken during November and December 1911 with the object of determining the source of infection in a series of cases of anthrax which occurred in the same yarn mill. The investigation resulted in proving that anthrax spores were present in a variety of East India wool and in the yarn manufactured therefrom.