Hess on Glaciers: DR. HARRY FIELDING
REID. Fry on Varnishes of the Italian
Violin Makers: PROFESSOR A. H. GILL.... 507
Scientific Journals and Articles....
Societies and Academies :-

The American Mathematical Society: PRO-
FESSOR F. N. COLE. The New York Acad-
emy of Sciences, Section of Geology and
Mineralogy: PROFESSOR A. W. GRABAU.
The Torrey Botanical Club: EDWARD BERRY.
The Philosophical Society of Washington:
CHARLES K. WEAD. The Conference of
Neurology and Vertebrate Zoology of Cor-
nell University: PROFESSOR BURT G.
WILDER. The American Chemical Society,
Northeastern Section: PROFESSOR ARTHUR
M. COMEY

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THE SIXTH ANNUAL MEETING OF THE SOCIETY OF AMERICAN BACTERIOLOGISTS.

THE sixth annual meeting of the Society of American Bacteriologists was held at the Laboratory of Hygiene, University of Pennsylvania, Philadelphia, Pa., on December 27 and 28, 1904.

The opening address was by President F. G. Novy, of the University of Michigan, on 'The Hematozoa of Birds.'

On the Hematozoa of Birds: F. G. Novy, University of Michigan.

An abstract or partial summary of the results obtained in this study appeared in American Medicine, November 26, 1904. The work in full will come out in two papers, the first of which, dealing with the Trypanosomes in birds, will appear in the second number (1905) of the Journal of Infectious Diseases; the second paper, dealing with the Cytozoa, may be expected in the third number of that journal.

The Effect of Freezing on Bacteria: ERWIN F. SMITH and DEANE B. SWINGLE, U. S. Department of Agriculture.

More than 100 freezings were made using about a dozen different bacteriasaprophytes and plant and animal pathogenic forms. Quantitative determinations were made in all cases. With the exception of Bacillus radicicola, all of the exposures were made in +15 peptonized beef bouillon, using cultures 24 to 48 hours old. Part of the freezings were made in liquid air, the time of exposure varying from 10 minutes to 24 hours, but usually one half hour. The rest were made in salt

and pounded ice, the time of exposure being 2 hours. The freezings were made in 5 c.c. portions of bouillon in test-tubes of resistant glass. The thawings were made in tap water at 16° to 18° C. The inoculations for each set of plates were made in the same way, i. e., usually with the thinnest meniscus it was possible to obtain across a 1-mm. platinum oese. The petri dishes were carefully selected, those taken being approximately 9 cm. in diameter, with flat bottoms. The regular method of work was to make three poured plates (checks) from the inoculated tubes after insuring thorough diffusion, which was obtained by stirring with the platinum rod, shaking and allowing to stand one half hour. The tube was then immediately lowered into the liquid air and frozen slowly from the bottom up to avoid cracking. (This usually required four minutes.) As soon as the one half hour or other predetermined time of exposure had elapsed, the tube was removed, warmed for about 3 minutes in the laboratory air and then thawed in water (which usually required another 5 minutes). As soon as the thawing was completed, three more poured plates were made, and these together with the three check plates were then incubated in the dark at 30° C., until the colonies were in good condition for counting-a period varying, according to the species, from one to several days. The plates were all put on a leveling apparatus as soon as poured, and in general the distribution of the colonies in the nutrient agar was very uniform. When the plates were sown thin enough, the entire surface was counted (60 sq. cm.); for the thicker sowings the average of 10 or 12 sq. cm. was used, or of one half the plate.

The following samples

from two of the thirty or more slides exhibited will give a general idea of the method and results:

The following conclusions may be drawn: (1) The effect of very low temperatures has been greatly overestimated. As destructive results were obtained with salt and pounded ice (-17°.8 C., or less) as with liquid air. (2) The critical point appears to be somewhere around 0° C. If an organism can pass this point in safety, it is believed that even absolute zero (-273° C.) would not harm it. (3) Some individuals of each culture were able to endure unharmed the temperature of liquid air (-190° C.), although this was often only a small proportion of the whole number. (4) Repeated freezings and thawings reduced this number very gradually to nothing, but ten freezings and thawing (in course of eight hours) did not kill all of the individuals of P. campestris, although it reduced the number in the bouillon to such an extent that three one-millimeter loops gave three sterile plates. (5) This resistance to freezing is believed to be due

to absence of water in the resistant cells, these cells behaving like endospores, although not known to be endospores (i. e., from species not known to produce endospores). Possibly these resistant cells are to be considered as arthrospores. (6) Endospores freed from non-sporiferous vegetative cells by heating in the water-bath for fifteen minutes at 70° C. were not in any way injured by freezing (two species), and this would seem to be an added proof that the protoplasm of such spores is destitute of water, a conclusion already reached by various observers on account of their behavior in boiling water and streaming steam.

So far as any general inference can be drawn from experiments made only in bouillon, we may conclude that bacteria are injured by freezing to very different degrees, behaving in this respect like the higher plants and animals. Many kinds, like Bacillus typhosus, are destroyed in great numbers even by short freezings, while other forms, like Bacillus sorghi, are rather resistant. The former idea that bacteria in general are not harmed by freezing is untenable. It was based on qualitative tests which are incapable of showing the true state of affairs in the exposed culture. Probably an enormous number of bacteria are destroyed by every winter, and those which survive come through in the form of endospores or some other resistant shape. These experiments confirm and extend those of Prudden, Park and Sedgwick and Winslow. They will be repeated, freezing in water, and will be extended to include some additional species, and will probably be published by the U. S. Department of Agriculture.

The Viability of B. Dysenteria Shiga: W. D. FROST and R. WHITMAN, University of Wisconsin.

Four strains of this organism were test

Of

ed. One was the Shiga type. The others belonged to the Flexner-Harris type. these one was the Harris culture and the others were from Duval and Bassett's series of summer diarrhoea cases. The viability was tested by drying the organisms on articles of merchandise, dried food substances and in sterile distilled water and milk, under various conditions. A summary of the conclusions reached follows: the B. dysenteria when dried on articles of merchandise, as paper, cloth and wood, dies rapidly in from four to nine days at the temperature of 17-20° C. On dried food substances, as bread, rice and albumin balls, this germ may live for days. In some cases it is able to live over a month. In sterile distilled water the life of the germ is very short, rarely maintaining itself more than a week. In sterile milk the germ can live until the medium is dried up. The different strains vary in their viability under given conditions, the Shiga type culture being distinctly more frail than cultures of the Flexner-Harris type, the effect of temperature in modifying the viability of the germ being important. At a temperature of 38° C. it will live from only one half to one fourth of the time that it will live at a temperature of 17-20° C.

Pseudomonas Campestris (Pam.) Smith: H. A. HARDING and M. J. PRUCHA, EXperiment Station, Geneva, N. Y. Pseudomonas campestris (Pam.) Smith is a yellow non-spore-forming plant parasite. It attacks cabbage, cauliflower and allied plants by way of their fibrovascular system.

A study of its resistance to desiccation. showed that while it died when exposed on sterile cover-slips for a few days (in our experiments not surviving a ten-day exposure), it retained its vitality on cabbage seed for more than a year. Apparently

no loss of pathogenicity resulted from this long exposure to unfavorable conditions. Cabbage plants inoculated with pure cultures, obtained from seed thirteen months after infection, showed a blackening of the veinlets in the leaf and other evidences of disease at the end of sixteen days.

At a time when so much stress is being laid upon the quickness with which pathogenic organisms are destroyed in nature these observations should tend to check hasty generalizations. (To be published in full in Centralbl. f. Bakteriol., etc., II. Abt.)

The Demonstration of the Flagella of Motile Bacteria and a Simple Method of Making Photomicrographs: EDWARD W. DUCKWALL, Aspinwall, Pa.

I found that the methods for flagella staining described by the old authors had to be modified. I divided the motile bacteria into six classes for staining purposes:

1. Bacilli which grow like typhoid, such as typhoid and colon. Bacteria resembling typhoid are actively motile bacteria. The material is transferred to a large drop or two of distilled water, previously boiled. A fine platinum loop, about half the usual size, should be used. The finest specimens of bacteria will swim to the outer edges of the water.

2. Bacilli which produce wrinkled or folded growths, such as Mesentericus fuscus. In order to get a good preparation from the bacteria which produce wrinkled or folded growths the agar should be streaked in the morning and carefully watched for the first appearance of growth.

3. Bacilli which send out a thin, almost transparent growth over the surface of the agar, such as Bacillus subtilis and Bacillus megatherium. In order to get a good preparation from the thin, transparent, spreading growth a curved platinum wire is used to collect the bacteria en masse and

transfers are made to the distilled water with the small loop.

4. Bacilli which produce slime, such as Bacillus vulgatus and Bacillus viscosus. The slime which collects between the flagella of the slime-producing bacteria can be precipitated by shaking a water suspension with chloroform. A very young growth is used and transfers are made to about 1 c.c. of water until it is made very cloudy. This suspension is then shaken with chloroform and the coverglass preparation is made from the water above the chloroform.

5. Bacilli which produce pigments, such as Bacillus prodigiosus and Bacillus cyanogenes. Bacteria which produce pigments soluble in chloroform are treated in the same manner. Those whose pigments are soluble in water and not in chloroform I prepare by holding the cover-glass under the tap after fixing the preparation in the flame previous to adding the mordant.

6. Anaerobic bacteria, such as Bacillus tetanus, ædema and symptomatic anthrax, etc. The best results with anaerobic bacteria are obtained as follows: The medium is two per cent. glucose agar in slants and the inoculation is made back of the slant between the agar and the wall of the tube. I slide the needle back of the slant and let it fall forward, I introduce two or three drops of a young bouillon culture and replace the agar. By excluding oxygen and maintaining a blood temperature for thirty-six hours a fine growth is usually obtained.

I prefer the No. 1 round cover-glasses. For removing the grease they are covered with sulphuric acid, which is poured off after they have stood one day, and they are then covered with bichromate of potassium. After several hours this is poured off and they are washed with distilled water and transferred to a jar containing absolute alcohol, where they remain until

ready for use. A single cover-glass is removed with clean forceps from the alcohol and dried with clean linen without touching it with the fingers. It is then taken in the forceps and passed several times through the Bunsen flame.

The fixing agent is a mordant and the stain is carbol gentian violet or preferably carbol fuchsine.

Mordant.-2 grams tannic acid; 5 grams cold saturated solution ferrous sulphate (aqueous); 15 c.c. distilled water; 1 c.c. saturated alcoholic solution of fuchsine.

To these ingredients I add a one per cent. solution of sodium hydroxid, from 5 to 1 c.c.

After filtering, the mordant should be of a reddish-brown hue, and it must be used within five hours after it is made.

Carbol Fuchsine.-Put about one gram of granulated fuchsine in a bottle and pour over it 25 c.c. of warm alcohol; shake, let stand for several hours, and dilute four or five times with a five per cent. solution of carbolic acid.

A small loop full of the clouded water is transferred to the cover-glass. A spread consisting of several parallel streaks is best. The glass, held by the forceps, preparation side up, is passed down on to the Bunsen flame and instantly removed. The mordant is then poured on, just enough to cover the surface without flowing over the edges. After one half to one minute the mordant is completely washed off under the tap; a small quantity of alcohol is then poured on to the surface and instantly washed off. Then cover the surface with carbol fuchsine or carbol gentian violet, which is allowed to stand on the coverglass for about one half minute. We then heat it so that steam is given off and, after drying thoroughly, treat with xylol, immediately draw off the xylol with filter paper, drive off what remains with heat and mount in xylol balsam.

A Simple Method of Making Photo

micrographs.-The camera is about twice as long as the ordinary 4 x 5 camera, and the photomicrographs are taken with the camera in a horizontal position. It must be steady and the microscope stand should be substantial, with the fine cone adjustment. Much depends upon the objective. I have found none equal to the one-twelfth oil immersion objective and No. 6 compensating eye-piece made by the Spencer Lens Co. The best plates are the isochromatic or orthrochromatic swift plates which are corrected for colors. I have found the acetylene radiant preferable to gas, oil or electric light. The only screen I ever use is green glass. Printing from the negatives on glossy Velox brings out the best detail. The glossy Velox is then ferroplated, which makes a beautiful photograph.

(Complete paper will be published in the New York Medical Journal; also in the Canner and Dried Fruit Packer, 1905, XX., No. 5, p. 23, with many illustrations.)

Principles of Classification of Bacteria: F. D. CHESTER, Delaware Agricultural College.

As far as possible morphologic characters should be the primary basis of classification. The generic system of Migula is proposed, based upon character of flagellation.

With sporogenous bacteria, character of spores, mode of germination, form of sporangia, and orientation of the cellular elements are useful toxonomically. With the asporogeneous bacteria grouping must be based largely upon physiological characters.

The proposed division of genera into groups is based upon leading characters in the order named: (1) Spore formation, (2) relation to oxygen, (3) liquefaction of gelatin, (4) fermentation of lactose, (5) fermentation of dextrose, (6) fermentation