282 KOPINESS IN MILK, ETC. 



164. Ropiness in Wine 



was formerly attributed to a coagulation of the albuminoids, a 

 hypothesis corrected in 1856 by G. MULDER (II.), who traced 

 the chief source of this malady to the conversion of sugar into 

 vegetable mucilage. Young white wines, in particular, fall vic- 

 tims to the disease, which in its incipient stage produces a faint 

 opalescence, followed by gradually increasing turbidity, until, 

 finally, the liquid becomes thick, and by degrees so viscid that 

 it can be drawn out into threads a yard or so in length, and can 

 scarcely be poured out of the bottle. The flavour is disagreeably 

 slimy and insipid, though the odour (bouquet) is almost unaltered. 

 In France the malady is termed " Maladie de la graisse," or gene- 

 rally " Vin filant " or " Vin huileux" and the Italians style it 

 "Vino filante." The earliest microscopical studies on this point 

 were made in 1861 by PASTEUR (XII.), who found a very large 

 number of fission fungi always present in ropy wine, and also 

 that by transferring a little of the liquid to sound wine of the 

 same class, the disease was quickly communicated to the latter. 

 He described two kinds of cell form : small cocci united in chains 

 (streptococci), and irregularly shaped cells somewhat larger in 

 diameter than those of yeast. The chief products of the mucinous 

 fermentation set up in wine by this mixture of organisms were 

 found to be gum, mannite, and carbon dioxide. Their ratio was 

 represented by Pasteur in the form of an equation as follows : 



24C 6 H 14 O 6 + I2C0 2 + I2H 2 O. , 

 Saccharose. Gum. Mannite. 



These proportions were admittedly variable, but this was ex- 

 plained by Pasteur by the supposition that the one species of fer- 

 ment produces more mannite, the other more gum ; and Monoyer, 

 in 1862, attempted to represent these reactions by splitting up the 

 equation into two. Some observations on the aforesaid strepto- 

 coccus have also been published by E. DUCLAUX (X.). 



The thoroughgoing microscopical investigations performed by 

 J. NESSLER (II.) showed that the streptococci described by Pasteur 

 are frequently absent, or only present in very small numbers, in 

 ropy wine ; whereas, on the other hand, the presence of certain 

 unusually plentiful, extremely minute round bodies can always be 

 detected. Subsequently a few samples of ropy wines were exa- 

 mined by E. KRAMER (II.), mainly with the object of obtaining 

 pure cultures of the organisms causing the malady, but this object 

 has not yet been successfully accomplished. By means of the 

 dilution, method approximately pure cultures of such a fission 

 fungus have been prepared; and the name of Bacillus viscosus vim 

 has been given to the organism. It occurs in the form of rods, 

 0.6-0.8 p broad and 2-6 p long, frequently united as many-jointed 

 chains, and capable of producing ropiness in white wines in the 



