1048 SUMMAEY OF CURRENT RESEARCHES RELATING TO 



interesting study as to the effect of siiuliglit on the vitality of micro- 

 cocci. He experimented on six species, more or less distinct, dis- 

 covered in various cases of disease (clou de Biskra, pemphigus, 

 rheumatic nodosities, impetigo contagiosa, &c.). The influence of 

 the sunlight varied with the age of the microhes, with the absence or 

 presence of cultivating fluid, and with the season. He did not dis- 

 criminate between the influence of the light and of the heat of the sun, 

 except in so far that he did not subject the micrococci to temperatures 

 exceeding those most suitable to their development (i. e. between 

 30° and 40° C). In ordinary circumstances, where the sun's heat is 

 frequently much greater, the vitality of the microbes will be con- 

 sequently much less. (1) Young micrococci in decoction of veal, living 

 on an average more than a year when not subjected to sunlight, were 

 killed by forty days' exposure to the feeble and intermittent light of 

 the spring sun of May and June, while in July a few days sufficed 

 to render them innocuous, and fifteen days to kill them. (2) When 

 the micrococci were allowed to dry, protected only by the thin residue 

 of the evaporation of a drop of the cultivating fluid, they were killed 

 by eight days' exposure, between May 26th and June 3rd, while in July, 

 two or three days were enough, even in a window with only four hours' 

 sun, and with a temperature never above 39°. The appai'ent absence 

 of spores is probably largely the explanation why the limits of 

 vitality are more restricted than in the case of bacilli. Since a few 

 hours' exposure is enough to kill the micrococci, we have an interesting 

 explanation of the abundant dead germs in the air, of the restricted 

 area of their fatal potency, except when conveyed by media where 

 they are protected from sunlight. In a word, as he says, sunlight 

 is the most universal, potent, and economic antagonist of these our 

 most subtle enemies. 



Decomposition and Fermentation of Milk.* — In continuation of 

 previous investigations on this subject,f Dr. F. Hiippe describes distinct 

 organisms which he finds to be invariable accompaniments of lactic 

 fermentation. One of these he isolated on nutrient gelatin, in 

 the form of white shining flat minute beads. This organism transforms 

 milk-sugar and other saccharoses into lactic acid, with evolution of 

 carbonic acid gas. It is rarely found in the saliva or dental mucilage. 

 In them are two micrococci, which cause the production of lactic acid, 

 which manifest diflerences in their development on cultivation. There 

 were also two pigment-forming bacteria, the Micrococcus prodigiosus, 

 which produces intense red spots, and the yellow micrococcus of 

 osteomyelitis. These flve bacteria are so different and so constant in 

 their properties, that they must be regarded as distinct species. In 

 addition to these, there is in milk an organism resembling Mycoderma 

 aceti which transforms milk-sugar into gluconic acid. 



Systematic Position of the Bacteriacese.l — M. J. Kiinstler dis- 

 cusses this subject in detail, and argues that the Schizomycetes 



* Deutsch. Medicin. Woohensclirift, 1884. See Bot. Centralbl., xxii. (1885) 

 p. 237. 



t See this Journal, iv. (1884) p. 786. 



i Journ. de Microgr., ix. (1885) pp. 248-58, 295-307 (1 pi.). 



I 



