552 THE POPULAR SCIENCE MONTHLY. 



of heat, so as to destroy the yeast-germs. There was no possibility of 

 doubt as to the destruction of these germs and the prevention of any 

 further change, but it might well be asked whether the delicacy and 

 bouquet of certain wines would not be endangered by the effects of 

 heating. Long-continued experiments prove not only that heating is 

 an excellent method for preventing sickness in wines, but also tliat, in- 

 stead of impairing their exquisite qualities, it ripens and strengthens 

 them. The recorded minutes of tastings officially performed during the 

 past year by several members of the syndical wine commission, at the 

 suggestion of M. Pasteur, contain decisive testimony on this point. 

 Fine Burgundy wines, heated in bottle seven years ago to temperatures 

 varying between 131° and 149°, appeared, at the end of that time, su- 

 perior to the same wines not so treated. Persons who spoke with some 

 authority, M. Pasteur says, declared that heating would in time de- 

 prive the wine of its color. The contrary is the case, when the air is 

 excluded during the process ; the color grows livelier by heating. It 

 was said tliat heating would in time alter the bouquet of fine wines, 

 giving them dryness and too great age. On the contrary, the bouquet 

 seems to be heightened with the lapse of time, more positively than 

 with wines not heated. In the case of chambertin and volnay partic- 

 ularly, the tasters noticed this fact. M. Pasteur was led by these 

 studies to investigate the cause of the aging of wines, and he discov- 

 ered that the phenomenon was due to slow oxidation. Wine kept in 

 glass tubes completely filled and closely sealed does not age. By in- 

 creasing and regulating the aeration of wine, and particularly combin- 

 ing it with heating, he succeeded in manufacturing in one month ex- 

 cellent old wine. In short, oxygen and heat, acting on wine in certain 

 proportions, promote instead of hindering the development of those 

 volatile principles to w^hich the liquid owes its perfume and part of its 

 flavor; but this discovery is additional to those sought. What M. 

 Pasteur did chiefly look for and did find, in giving exact and methodi- 

 cal rules for heating whines, is a process, applicable on a great scale, 

 for preventing the diseases from which the common vineyard products 

 so often suffer, and that fortunate application is a result from his re- 

 searches on fermentation generally. In the same w^ay, in consequence 

 of the examinations he undertook as to the share of microscopic organ- 

 isms in the diseases of silk-worms, he was led to presqribe a practical 

 way of hindering the development of these organisms, and thus pre- 

 venting the malady. 



When we inject into the subcutaneous cellular tissue of a living 

 animal a putrefied or septic liquid, that is, one containing those thread- 

 like corpuscles known by the name of vibrios and bacteria, it some- 

 times happens that the animal experiences no inconvenience. Dogs 

 particularly resist with vigor the poisonous influence of such a fluid, 

 but the case is different with other species, and notably with rabbits. 

 The system becomes the seat of grave phenomena, almost always mor- 



