Septembek 12, 1913] 



SCIENCE 



371 



considerably with the different cultures, a card- 

 catalogue system has been devised. Under this 

 system each culture is represented by a card, upon 

 which are recorded all the dates of transplantation 

 as the fresh cultures are made. The cards are 

 kept in a file, with each card placed under the date 

 at which the next transplant of its culture is 

 necessary. The work upon the cultures each day 

 is carried out in accordance with the cards filed 

 under that date. During the intervals between 

 transplants, all cultures except the B. influenzw, 

 gonoeoccus and meningococcus are kept cold. Five 

 dates of each culture are kept and the tube of 

 most recent date is unopened. In order to keep a 

 large number of cultures constantly on ice, we 

 have had a refrigerator constructed especially for 

 this purpose. The refrigerator, well insulated, is 

 about seven feet long, six feet high and two feet 

 in depth. It is divided into six large compart- 

 ments, three above and three below. The middle 

 compartment of the upper row contains the ice, 

 and it is always filled to its capacity, .500 pounds. 

 This quantity of ice maintains a temperature of 

 10° to 15° G. throughout the entire refrigerator. 

 The refrigerator is well drained and the open 

 framework of the interior allows free circulation 

 of air. Five compartments are devoted to the 

 cultures. These compartments are provided with 

 drawers, which slide in grooves and are easily 

 removed. Each drawer is of such dimensions that 

 two crates of cultures fit end to end within it. 

 The total number of drawers is 63 and the total 

 capacity 1,600 cultures. The front of each drawer 

 is provided with a groove into which a card is 

 fitted designating the contents of the drawer. 

 With this refrigerator and our system of trans- 

 planting we are able to keep ready for immediate 

 use a fresh supply of all the cultures necessary for 

 the preparation of bacterial vaccines. 



A Refinement of the Technic of Quantitative Bac- 

 teriological Analyses: W. D. Frost, Boston, 

 Mass. 



It is generally recognized that the measured 

 quantities of water, used for dilution, lose in 

 volume during sterilization and upon standing. 

 The exact amount of this loss or the means of 

 preventing it are apparently not generally under- 

 stood. In an extended series of experiments it is 

 found that the loss varies from 1 to 8.8 per cent, 

 and that the average is 5.07 per cent. Various 

 types of autoclaves are tested and it is found that 

 there is considerable variation in the different 

 types. The loss is evidently due to the ebullition 



and escape of steam, especially during cooling. 

 This loss can be prevented by closing up the auto- 

 clave cold, as is frequently done in sterilizing 

 blood serum. When closed in this way the auto- 

 clave is not always efficient in the time or at the 

 pressure ordinarily used. In order to insure 

 sterilization it will be necessary to extend the 

 time, increase the pressure or sterilize on two 

 consecutive days. The evaporation due to stand- 

 ing a few weeks is equal to the loss in the auto- 

 clave. This is not prevented by a thin paper cap. 

 Paraffined paper is recommended, also cork stop- 

 pers covered 'by a thin layer of cotton instead of 

 an ordinary cotton plug. In using the bottles 

 after making the dilution it is suggested that the 

 sterile side of this cap be forced into the mouth 

 of the bottle with the cork. This permits efficient 

 shaking. 



The Significance of the Time at which Gas is pro- 

 duced in Lactose Peptone Bile: Willi.\m W. 

 Browne, Ph.D., College of the City of New 

 York. 



During the summer of 1912 routine bacteriolog- 

 ical examinations of oysters of Narragansett Bay 

 were made under the direction of Professor F. P. 

 Gorham, of Brown University, with the hope of 

 determining the extent of the pollution of the 

 oyster beds of Rhode Island by the sewage of the 

 neighboring cities and towns. The examinations 

 were made according to the methods proposed by 

 the American Health Association. Lactose pep- 

 tone bile was used as a presumptive test to indi- 

 cate the presence of members of the Bacillus coli 

 group and other lactose fermenters of intestinal 

 origin. (1) Lactose peptone bile tubes inoculated 

 with the shell liquor of oysters taken from 119 

 different beds produce the greater part of their 

 gas by the end of the forty-eighth hour. (2) 

 Lactose peptone bile tubes inoculated with the 

 shell liquor of oysters taken from polluted areas 

 produce almost all their gas by the end of the 

 forty-eighth hour. (3) Lactose peptone bile tubes 

 inoculated with the shell liquor of oysters taken 

 from districts comparatively free from pollution 

 produce the greater part of their gas by the end 

 of the seventy-second hour. (4) Consideration of 

 this temporal factor in the production of gas in 

 lactose peptone bile might aid in the determina- 

 tion of whether the pollution was recent or remote. 

 A Comparative Study of the Smith Fermentation 

 Tube and the Inverted Vial for the Determina- 

 tion of Sugar Fermentation : William W. 

 Browne, Ph.D. 



