March 6, 1903.] 



SCIENCE. 



379 



ganisms having the same characteristics as 

 B. coli are very widely distributed in na- 

 ture, and their presence, unless in consider- 

 able numbers, is not necessarily indicative 

 of recent ftecal contamination. 



On the Relative Viahility of B. coli and B. 

 typhosus tinder Certain Conditions: 

 Stephen DeM. Gage, Lawrence Experi- 

 ment Station. 



In various studies of both B. coli and B. 

 typhosus at the Lawrence Experiment Sta- 

 tion, a number of points of similarity in 

 the behavior of the two species under cer- 

 tain conditions have been noted, which ap- 

 pear to have a bearing on the interpreta- 

 tion of tests for B. coli. 



1. As regards sand filtration. With a 

 water to which both species have been 

 added, 99.9 per cent, of all the B. coli and 

 100 per cent, of the B. typhosus were re- 

 moved by an intermittent filter, and 99.8 

 per cent, of B. coli and 99.9 per cent, of 

 B. typhosus by a continuous filter. 



2. As regards the persistence of the two 

 organisms in a filter after infection of the 

 applied water has ceased, B. coli was found 

 to continue in the effluent from the inter- 

 mittent filter for 24 to 36 hours, and B. 

 typhosus only for two to three hours. 



With the continuous filter B. coli con- 

 tinued for four to six days and B. typhosus 

 for two days. 



3. Effect of cold without freezing. In 

 a water subjected to a temperature of 33° 

 F., about 90 to 95 per cent, of both species 

 were destroj^ed in 24 hours; a few organ- 

 isms of each, however, may live for a con- 

 siderable number of days. 



4. Elimination by freezing and viability 

 in ice. About 50 per cent, of the B. coli and 

 75 per cent, of the B. typhosus were de- 

 stroyed by fifteen minutes' freezing; after 

 one hour, 95 per cent, of the B. coli and 98 

 per cent, of B. typhosus were killed; and at 



the end of 24 hours over 99 per cent, of all 

 the organisms had disappeared. Of the 

 few organisms surviving, however, B. coli 

 were found alive after three months, and 

 B. typhosus after nine months, in the frozen 

 condition, these experiments being still in 

 progress at the present writing. 



5. Resistance to heat. Both species re- 

 sist temperatures up to 45° C. for five 

 minutes. At between 45° and 55° C. all 

 but a few individuals of each are destroyed, 

 these fcAV individuals, however, resisting 

 temperatures up to 85° C. at which tem- 

 perature all the organisms of both species 

 were destroyed. 



The effect of sunlight and the relative 

 viability of both species in both sterile and 

 natural waters are being studied, and from 

 the data at hand a similarity between the 

 two species will also appear. 



The Germicidal Properties of Glycerine in 

 Relation to Vaccine Virus: M. J. 

 RosENAU, Hygienic Laboratory, Wash- 

 ington, D. C. 



The bacteriological examination of many 

 dry points and capillary tubes of glycerin- 

 ated virus bought upon the open market 

 showed an excessive contamination, due 

 to an over-confidence in the germicidal 

 properties of glycerine. About one year 

 ago, of 41 dry points examined, there was 

 found an average of 4,807 organisms per 

 point; of 51 glycerinated tubes examined, 

 there was an average of 2,865 colonies per 

 tube, some individual tubes running as high 

 as 18,000. Following a publication of 

 these facts and the warning given to manu- 

 facturers that glycerine is not a substitute 

 for care, a great improvement in the bac- 

 teriological contents of glycerinated virus 

 on the market resulted. Thus, of 89 tubes 

 examined an average of only 28 organisms 

 per capillary tube was found as a result 

 of recent studies. 



