372 



SCIENCE 



[N. S. Vol. XXXVIII. No. 976 



During the sanitary survey of Narragansett 

 Bay conducted under the direction of Professor F. 

 P. Gorham, of Brown University, a comparison 

 was made of the efficiency of the Smith fermenta- 

 tion tube and the inverted vial as used in the 

 presumptive test with lactose peptone bile to indi- 

 cate the presence of members of the Bacillus coli 

 group and other lactose fermenters of intestinal 

 origin. Fermentation tubes and inverted vials 

 containing lactose peptone bile were inoculated 

 with the shell liquor of oysters taken from pol- 

 luted areas and the following results were ob- 

 tained : 



Percentage of Efficiency 



Cubic Centimeter 

 24 hrs. 48 hrs. 



Fermentation tube 84.6^ 94.3;^ 



Inverted vial 92,3;^ 96.1^ 



One Tenth 

 Cubic Centimeter 

 24 hrs. 48 hrs. 



Fermentation tube 86.5;^ 90.3^ 



Inverted vial 59.5^ 84.6,'^ 



One Hundredth 

 Cubic Centimeter 

 24 hrs. 48 hrs. 



Fermentation tube 32.6^ 55.7^ 



Inverted vial 23.0;^ 42.3;^ 



Hesistance of Microorganisms Suspended in Gly- 

 cerine or Oil to the Sterilizing Action of Heat: 

 C. J. Bartlett and F. B. Kinne. 

 Dreyer and Walker have recently reported the 

 results of heating spores suspended in glycerine 

 and oil. They show that spores in glycerine were 

 not killed with certainty after heating two hours 

 at IJ atmospheres, 2 hours at li atmospheres or 

 one half hour at 2 atmospheres. In our experi- 

 ments we have worked with the Staphylococcus 

 aureus, with the Bacillus anthracis and wdth the 

 Bacillus suitiliSj and with a bacillus with very 

 resistant spores, apparently the Bacillus vitalis. 

 These have been heated in glycerine, water, olive 

 oil, cottonseed oil and paraffin for different periods 

 at the temperature of boiling water and in the 

 autoclave at 7J lbs. pressure and at 15 lbs. pres- 

 sure. "The Staphylococcus aureus is quickly killed 

 in all of these, even at the temperature of boiling 

 water. The spores of the anthrax bacillus and of 

 B. subtilis are quickly killed in boiling water, 

 usually in three minutes or less. In glycerine they 

 have been found alive after one and one fourth 

 hour at this temperature and in oil after fifty 

 minutes, and in the autoclave after heating in oil 

 fifteen minutes and in glycerine in ten minutes at 

 7J lbs. In water they do not live after five min- 



utes at this pressure. The spores of the B. vitalis 

 are killed in about one half of these tests by heat- 

 ing in boiling water for two hours, while in oil 

 and glycerine they resisted this temperature for 

 two hours in every instance. After heating in the 

 autoclave they were found alive in oil at 15 lbs. 

 for two hours and in glycerine after one and a half 

 hour, but not longer. In water they were never 

 found after twenty minutes at 7J lbs. and after 

 ten minutes at 15 lbs. It is evident that spores 

 are more resistant to the action of hot oil and 

 glycerine than to that of hot water. 



The Comparative Viability of Fneumococci on 

 Solid and on Fluid Culture Media: L. J. Gil- 

 lespie, Hospital of the Kockefeller Institute for 

 Medical Research. 



The following facts have been observed: (1) 

 Broth which is perfectly suited for the growth of 

 copious cultures of the pneumococcus often re- 

 quires many more organisms (frequently a million 

 times as many) to initiate growth than does agar. 

 (2) Cultures which when fresh from the animal 

 body show a marked effect become on cultivation 

 upon artificial media indifferent in their require- 

 ments. (3) Certain cultures (of any strain) show 

 no effect even when fresh from the body. (4) 

 Differences in chemical composition of broth and 

 of agar play little or no part because an imitation 

 ' ' solid ' ' medium, prepared from filter paper and 

 broth, serves nearly as well as agar. (5) The 

 possibility that insufiScient aeration in the case of 

 broth plays any role is ruled out by comparing 

 agar plates with agar shake cultures. These phe- 

 nomena may be explained if we suppose that the 

 pneumococcus sometimes requires for its multipli- 

 cation that substances from the animal body be 

 present in the immediate environment of the cocci, 

 the concentration of which can be too far reduced 

 in the case of broth by diffusion aided by convec- 

 tion. If we suppose rather that the necessary sub- 

 stances are produced by the pneumococci them- 

 selves we may assume that such substances are 

 always necessary, and that during acclimatization 

 to artificial media the capacity for such metab- 

 olism is increased. 



Studies of the Suttilis Group: Karl F. Kellee- 



MAN and Edna H. Fawcett, Bureau of Plant 



Industry, Washington, D. C. 



The Suitilis group includes the spore-forming 



aerobic and facultative anaerobic bacteria which 



liquefy gelatine. Numerous cultures of members 



of this group have been obtained from various 



sources. Biometrical study of their acid produe- 



