120 LOUIS PASTEUR. 



moments, in the state of the wine, the right conditions 

 for their existence and multiplication ? 



The cause of these alterations having been found, a 

 mode of preventing the development of all these para- 

 sites had still to be sought. Pasteur's first endeavour 

 was to discover some substance which would be anta- 

 gonistic to the life of these ferments of disease, while 

 Charmless to the wine itself, and devoid of any special 

 ( smell or taste. But in this research success was 

 dependent on too many conditions to be easily attain- 

 able. After some fruitless trials, the thought occurred 

 to Pasteur of having recourse to heat. He soon 

 ascertained that, to secure wine from all ulterior 

 changes, it sufficed to raise it, for some instants 

 only, to a temperature of from fifty-five to sixty 

 degrees. His experiments were first directed upon 

 the disease of ' bitterness.' He procured some of the 

 best wines of Burgundy, wines of Beaune, and of 

 Pomard, of different years 1858, 1862, and 1863. 

 Twenty-five bottles were left standing forty-eight 

 hours to allow all the particles suspended in the wine 

 to settle ; for, however clear wine may be, it always 

 produces a slight deposit. Pasteur then decanted the 

 wine with minute care, by means of a syphon of slow 

 delivery. This last precaution was necessary to pre- 

 vent the deposit from being stirred up. \Vhen there 

 remained in each bottle only one cubic centimeter of 



