CHAPTER XII 



THE PROFESSOR: AVIGNON (CONTINUED) 



WHEN Pasteur called upon Fabre, at 

 the beginning of his investigation of 

 the silk-growing industry, he was also greatly 

 interested in the improvement of wines by 

 the application of heat. 1 Thus it was that, 



1 Everybody knows to-day that heat kills, or so far 

 enfeebles as to render inoffensive, the microbes that in- 

 fact liquids and make it impossible to preserve them. 



This again is one of Pasteur's happy discoveries, as 

 is conveyed by the very verb to pasteurise, which means 

 " to protect against microbes by the action of heat." We 

 pasteurise milk, beer, wine, etc. 



The ancients used to practise the heating of wines. 

 In the house of St. John and St. Paul, discovered in Rome 

 in 1887, beneath the church dedicated to the two martyrs, 

 who were both officers of the Emperor Constantine, 

 the excavators found beside the cellar and the amphora; 

 of wine, the little room with a fireplace known as the 

 jurnarium, which was used for heating wine and drying 

 fruit. 



The heating of wines was practised also at Meze, near 

 Cette, before Pasteur's discovery. 



But the ancient method of heating had nothing in com- 

 mon with pasteurisation. The merchants of Herault, 

 like the ancients, used to heat wine in order to modify 

 its flavour, to mature it more quickly. Pasteur, on the 

 other hand, heats it to keep it unchanged. To mature 

 wine it is heated slowly in contact with the air. To 

 preserve it, the wine must be rapidly heated to 122 F. 

 in a vacuum. The object and the method are altogether 

 different. 



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