188 PASTEUR: THE HISTORY OF A MIND 



thought of which already haunted him, he allowed him- 

 self to be seduced by the idea of studying the manufac- 

 ture of beer. Was it not possible to make it in France 

 as well as in Germany, and to free us through science 

 from paying tribute to the breweries across the Rhine? 

 Such was the ambition that took possession of him little 

 by little as he penetrated more and more into this diffi- 

 cult subject. To-day we may say that this ambition 

 has been realized as much by the efforts of Pasteur as 

 by the intelligent activity displayed by the French 

 brewers. At the present time, the best French beers 

 are equal to the best German or Austrian beers, and for 

 this progress the French brewers, in the Congress of 

 1889, gave the honor and credit to the labors and to the 

 book of Pasteur on beer. 



This book is not an ordinary book, not a kind of 

 theoretical treatise on brewing. It reflects so clearly 

 the varied preoccupations of Pasteur at this stage of his 

 existence, that I am obliged to draw attention to its 

 somewhat eccentric composition. Of brewing there is 

 very little said. The first chapter shows that the dis- 

 eases of beer are always due to the development of 

 microscopic organisms foreign to a good fermentation, 

 not at this time a new idea. The last chapter gives the 

 means of making pure and unalterable beers. And it 

 seems, in reality, that this is sufficient, and that one 

 might be content with saying to the brewers: This is 

 why your beers are bad, and here is the means of making 

 good ones ! 



It was, in fact, in these relatively simple terms that 

 Pasteur stated the problem in the beginning. But he 

 was not slow to see that the question was much more 

 complicated. An egg of a silkworm developed accord- 

 ing to a scientific formula is surely a good egg. A beer 

 protected from pathogenic ferments during its manufac- 



