lUWA ACADEMY OF SC1EN(;ES. 80 



solated lactic acid in milk in 1833; Turpin in 1837, supposed that the cause 

 ct souring milk came from the mammary gland and was contained in the fat glob- 

 ules. Schwann and Latour, 1837, had laid the foundations to rationally explain 

 the process of fermentation, making it certain that organized living beings caused 

 the changes observed in a fermenting substance. Fuchs '-" was the first in modern 

 times to examine luilk microscopically. He found two germs; one he termed monas 

 and the other infusor. Blandeau, 1847, incorrectly ascribed lactic acid fermentation 

 to yeast (Torula) and the common blue mould {PenkiUium). Liebig supposed that 

 fermentation was a property of all albuminoids and this view gained credence in 

 many quarters. But we must pass over these stumbling blocks in the history of 

 this work and give in rapid succession the vital points which have made it pos- 

 sible to put the fermentations of milk on a high road to a successful use in prac- 

 tice. Pasteur, in 1837, thought souring of milk was due to an organized Ferment 

 lactique; he also recognized that other organisms were present; to distinguish the 

 two, he called it Levenre lactique caused by his Vibrio huturiciis^^". This germ 

 was capable of standing a much higher temperature than the lactic acid organisms. 

 In 1874 Lister, by using bacteriological methods, separated his Bacillus lad is, which 

 we have seen led him to erroneous ideas. 



Hueppe'3' somewhat later, 1884, made ajthorough study of souring milk and 

 referred Lister's Bacillus lactis to one which he described as Bacillus acidi lactici. 

 In a second paper he concluded that souring was not caused alone by this species, 

 but several. Marpmann,'^- Conn,'^^ Storch,'^^ Weigmann'^^ and others have all 

 shown that species of lactic acid germs are numerous. The power of changing 

 milk sugar to lactic acid is not conSned to Saprophytic species, but some of the 

 pathogenic, like the Micrococcus £of osteo-myelitis^e bas the power coagulating 

 the casein of milk. Some of the chromogenes are very active in this direction. 

 The Bacillus prodigiosns which often causes red milk in Europe, has this 

 power. It is the famous blood-portent, connected with several superstitions, and 

 certain lesions of the teats, which were supposed to cause bloody milk, is due to 

 nothing more than the development of this bacterium, which may form lactic acid. 

 Schottelius and Wood'^" have pointed out tie interesting fact that as the tem- 

 perature rises the power of forming pigment is lost " and, if it is grown on potato 

 or bread paste, for example, in an incubator at blood heat instead of at the tem- 

 perature of the room, the color is gradually lost and the culture no longer smells 

 of herring brine, but the power of forming lactic acid from milk sugar, with the 

 accompanying precipitation of casein, is frequently increased, so that it would 

 appear that the energy required for building up pigment was, in this case, directed 



iMMag. f. d. Ges. Thlerlieilkunde, 1841. 



130 Hoffmann, 1869, also described two species, a motile ano anon-motile; the latter 

 he thought caused the souring of milk. 



isiUntersuchungen uber die Zersetzungen der Milch durch MiKro-organismen 

 mitth, aus dem K, Gesundheitsamte, Vol. II.. 1884, Deutsche Med, Wochenscrh, 1884, 

 No. 48. 



i32Ueber die Erreger der Milchsaeure Gaehrung Ergaenzungshefte, Z., Centrallblatt 

 f Allg, Gesundheitspflege.Vol. II., p. 117. 



i33Storrs' School, Conn, Agr. Exp. Station. 1889, p. 82: 1890, p. 136; 1891. p. 192. 



i34Nogle Cndersogelser over Flodens Syrning, etc. 



i35Die Bakteriologie Im Dieuste der Milchwlrtschaft Milch Zeitung, 1891, Nos. 19 

 and 20. 



i36Krause, see "Alfred Jorgensen Micro-organisms and Fermentation, English 

 translation, p. 63. 



i37Biologische Untersuchungen ueber den Mikrokkus'prodiglosus, Leipzig, 1887, p 

 185. See Sims Woolhead Bacteria, etc., p. 11. 



