Diseases of Swine 461 



the entire liquid finally undergoes putrefactive decom- 

 position. The disease is more frequent in southern than 

 in northern countries and often involves extensive pe- 

 cuniary losses. The bacterial nature of the disease is 

 proved, not only by the presence of large numbers of 

 bacteria in diseased wine, but, also, by direct inoculation 

 of sound wine with a minute quantity of diseased wine. 

 The presence of large amounts of protein favors the 

 development of the disease, while the presence of any 

 but minute quantities of acid retards it. It has been 

 recommended, therefore, that citric acid be added to 

 young wine as a preventive against the loss of color. 



Mannitic fermentation. This disease of wine is 

 familiar to wine-growers. It is most prevalent in warm 

 countries, largely because the bacteria causing the dis- 

 ease will develop best at higher temperatures. The dis- 

 ease is characterized by the conversion of the sugar into 

 mannite. Still another common disease, the bittering 

 of wine, has also been traced to* bacteria. This disease, 

 which usually affects only red wines, is manifested by 

 a reduction of acidity, the loss of color, and the deposi- 

 tion of a sediment on the bottom and walls of the con- 

 tainer. Objectionable tastes and odors are likewise 

 developed in the wine and finally render it worthless. 



The diseases of fermented liquors already enumerated 

 by no means exhaust the list. There are others that are 

 similarly responsible for serious injury to stored wine. 

 Climatic conditions, locality, and the methods of manu- 

 facture employed, are factors of importance in influen- 

 cing the character and prevalence of such maladies. 

 Much bacteriological and chemical work has already 



