334 EXPERIMENT STATION RECORD. 



On the apparent identity of tlie cultural reactions of Bacillus coli com- 

 munis and certain lactic bacteria, S. C. Prescott [Ahs. in Science, n. ser., 15 

 {1902), No 375, p. 363). — While engaged in studying certain lactic bacteria the author 

 noted the great similarity presented by some of the cultures to those of B. coli com- 

 munvi, and he has carried on investigations with a large number of lactic-acid-pro- 

 ducing organisms, comparing their cultural reactions with those of the above species. 

 Cultures were isolated from 47 different media. All of these were tested, and their 

 growth and morphological characters noted. Of the 47 cultures examined, 25 gave 

 typical colon reactions, 6 gave a weak response to tests, and the others failed. Regard- 

 ing the source of these bacilli, the author suggests that they may ))e true colon bacilli 

 from sources which can only l^e conjectured; or they may be lactic-acid organisms, not 

 absolutely identical, yet almost impossible of differentiation from the colon bacilli. 

 The latter view the author regards as the more probable. This work has a very 

 practical sanitary bearing and seems to indicate that too much reliance can not be 

 placed upon the so-called colon test of jiotable waters. 



Toxicity of water toward pathogenic bacteria, H. L. Russell {Abs. in Science, 

 n. ser., 15 {1902), No. 375, p. 364). — A preliminary report is given on the action of 

 natural water on the vitality of various organisms, particularly pathogenic organisms. 

 When typhoid and colon organisms were inoculated in boiled waters (surface, deep 

 well, and spring) growth generally occurred. This was more marked with the colon 

 than with the typhoid organisms, and was most pronounced where the seeding was 

 light. When the same cultures were exposed to the action of water filtered through 

 a Chamberland or Berkefeld filter, or to etherized water in which the anaesthetic 

 had been removed by aspiration, growth not only did not take place but the numerical 

 content was greatly reduced, so that the cultures, became sterile within 24 hours: 

 Tests showed that if filtered water was heated to 60° C. for 10 minutes it lost its 

 toxic power. The origin of the toxic substances is ascribed to the development of 

 water bacteria. After incubation for 33 days, this water was again filtered and found 

 toxic for typhoid and colon bacteria, and upon heating it again lost its toxicity. 

 Some bacterial species develop in standing water, seeming to indicate their ability to 

 tolerate the toxins. 



Effect of low temperatures of liquid air on pathogenic organisms, C. M. 

 Belli {Pub. 1st. Ig. Univ. Padova, 2 {1902), XII, pp. 7; extr. from Riforma Medica, 

 XVIII, No. 19). — An account is given of experiments with chicken-cholera bacilli 

 and spore-bearing and nonspoi'e-bearing forms of bacteria of carbuncle, which were 

 subjected for 9 hours to the action of the temperature produced by liquid air. The 

 results show that this temperature, which was al)out —190° C, not only checked 

 the development of the bacteria but caused an actual diminution in the number of 

 colonies present by destroying some of the least resistant. 



On the germicidal action of the organic peroxids, F. G. Now and P. C. 

 Freer {Abs. in Science, n. ser., 15 {1.902), No. 375, pp. 365, 366).- — The authors have 

 conducted a series of experiments with a view of ascertaining the correct explanation 

 of the action of certain metals and of sunlight on bacteria. It is known that certain 

 substances exert a marked effect upon the formation of benzoyl acetyl peroxid, and 

 this served as a basis for the view that metals act upon bacteria by giving rise to 

 energetic peroxids. In order to substantiate that theory the authors have investi- 

 gated the action of a number of known organic peroxids, some of which have proved 

 wholly inert, while others exert pronounced and remarkable germicidal properties. 

 With reference to diacetyl peroxids and benzoyl acetyl peroxid, it is shown that 

 these bodies are chemically and bacterially inert, but on contact with water they 

 imdergo hydrolysis and give rise to the extremely energetic acetyl hydrogen and 

 benzoyl hydrogen peroxids. A solution of 1:3,000 of these is capable of destroying 

 all pathogenic bacteria, and even some very resistant spores, within one minute. 

 The germs of cholera and typhoid fever added to tap water are promptly destroyed 



