CHAPTER XXIX. 



ROPINESS IN MILK, WINE, BEER, AND OTHER LIQUIDS. 



162. Ropy or Viscous Milk. 



THE first attempt at a scientific study of this malady was made in 1847 by 

 GIRARDIN (I.), who hoped to elucidate it by chemical analysis, and sought the 

 cause in the defective composition of the fodder. This complaint may develop 

 to a variable extent in milk. In the worst cases the thickened liquid can be 

 drawn out to a thin thread a yard or so in length. J. LISTER (I.), in 1873, was 

 the first to reproduce this complaint by inoculation, and thus indicated the 

 probability of a living source of infection. To ascertain this by microscopic 

 examination was the task essayed by SCHMIDT-MUHLHEIM (I.) in 1882, who 

 found that ropy sour milk contained an unusually large number of cocci i /* in 

 diameter, frequently united as chains, but also in many cases isolated, and in 

 the latter case apparently endowed with motile powers. Although at that time 

 suitable methods of pure culture were no longer lacking, this observer made no 

 attempt to utilise them in his researches. This omission was, however, soon 

 remedied by E. DUCLAUX (IX.), who prepared pure cultures of two species of 

 bacteria from ropy milk, both of which belong, morphologically, to the so-called 

 capsule bacilli. The powerful lustre of the greatly swollen mucinous envelopes 

 surrounding these cells is the first thing to strike the assisted eye, on which 

 account the generic name, Actinobacter (lustrous bacterium, star bacterium), 

 was applied to both organisms. Under their influence the milk yields alcohol 

 and acetic acid. 



To these two pests (known respectively as Actinobacter du lait visqueux and 

 A. polymorphus) a large number of others possessing similar powers have been 

 added by different observers ; e.g. a micrococcus discovered by HUEPPE (IV.) in 

 1884; the Bacillus mesentericus vulgalus, investigated by FLtiGGE (I.), and the 

 Bacillus pituitosi, a thick, slightly curved rod, discovered by LOEPFLER (III.). 

 Other allied species are : a streptococcus, described by HESS and BORGEAUD (I.), 

 and presumably identical with that observed by NOCARD and MOLLEREAU (I.) ; 

 and a bacillus, 1.2 /n broad and 2 p long, obtained by Schiitz from ropy milk, 

 and described by ST. VON RATZ (I.). In 1890, L. ADAMETZ (IV.) found in the 

 Liesing brook (which runs into the Danube in the south of Vienna) a capsule 

 bacillus, 0.7-1.2 p. long and 0.7 p broad, which he named Bacillus lactis viscosus, 

 and which is capable of turning both milk and cream ropy. It is fairly wide- 

 spread in nature, and was also detected by ADAMETZ (V.) in samples of milk 

 from the Sornthal (Switzerland). In addition to this, three other fission fungi 

 (named below) are found in Swiss soil, one of them being the Bacillus Guille- 

 beau c., which is not only dangerous to the cows (giving rise to inflammation of 

 the udder), but also produces various disturbances in the dairy by making the 

 milk " ropy " and the ripening cheese " blown." The facultatively anaerobic 

 Micrococcus Freudenreichii, 2 p. in diameter, discovered by A. GUILLEBEAU (I.), 

 is still more injurious to milk, since, whereas the other organisms just mentioned 

 act only at high temperatures approaching blood-heat, and therefore easily 

 avoidable in practice this coccus is active even at a moderate temperature, and 



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