1080 ^ EXPERIMENT STATION RECORD. 



The vitality of pathogenic and other micro-organisms in milk, 



F. V^VLAGUSSA and C. Oktona {Ann. Ig. Spar.; aha. in Nature., 63 

 {1901)., JVo. 163Jf., 2^' ^OJf). — The action of sunlight on bacteria in milk 

 was investigated, and as was to be expected from the opacity of the 

 liquid no deleterious effect was detected, except in the case of those 

 varieties which live on the surface of liquids and were, therefore, not 

 shielded from the svuishine. Another point of interest investigated 

 was the effect of inoculation into milk upon the elaT)oration of toxins 

 by the diphtheria bacillus. It was found that although this bacillus 

 produced toxin when grown in milk, its strength was less than when 

 grown in other culture media; moreover, a marked increase in the 

 strength of the toxin was noted when the cultures were kept in a cool 

 cellar instead of at the ordinary temperature of the laboratory. The 

 exact thermal death point of the tubercle bacillus in milk Avas also 

 reinvestigated, the authors concluding that exposure to temperatures 

 of 60, 70, or 80° C. is insufficient to guarantee the destruction of 

 this bacillus in milk. Milk freshly drawn from the cow, with precau- 

 tions insuring its sterility, was found to afford a better culture medium 

 for bacteria than after it had l)een artificially stiM'ilized by heating to 

 100° C. A bibliograph}' of the existing literature on the subject is 

 appended to the article. 



Pathogenic microbes in milk, E. Klein {Jour. Jlyg. [^Ckimhrldg(/\., 

 1 {lOOl), So. 1-, pl>- 78-.),')). — From an examination of 100 samples of 

 milk from country dairies, 7 were found by inoculation tests to con- 

 tain virulent tubercle bacilli; S samples contained Bac'dlus pseudo- 

 tuberculosis. A series of observations carried out for the purpose of 

 testing the viability of the tubercle bacillus in milk showed that this 

 organism grows well in milk kept at a temperature of 37° C. In one 

 sample of milk the tubercle bacillus of diphtheria was found, and 

 proved to be virulent when inoculated into the guinea pig. Bucterium. 

 dlpJdheroldes was also found in one sample. 



From the secretion of diseased udders the author isolated a number 

 of forms of streptococcus, which were found to vegetate readih' on the 

 surface of the gelatin and also in milk at a temperature of 37° C. 

 In 1 sample a pathogenic yeast was found, apparently differing in cul- 

 tural and physiological characteristics from the torula which liad pre- 

 viousl}' been obtained from human cancer. When inoculated into 

 guinea pigs, it produ -^d unusually large tumors. The organism 

 developed well on gelatin, ulkaline agar, lilood serum, and in milk. 



The distribution of the tubercle bacillus and pseudo-tubercle 

 bacillus in milk, and the biology of the tubercle bacillus, F. Klein 

 {Crnfbl. Bait. u. Bar., 1. Aht., 'J<S' {1900), .Xo. 4-o,jj/k 111-114).— The 

 author made an examination of 100 samples of milk from the London 

 market in thc^ condition in which it is received from the surrounding 



