PRODUCED BY ALCOHOLIC FERMENTS. 159 



made practical use of Spallanzani's experiments ; namely, he 

 published a method for the preservation of vinegar.* Accord- 

 ing to this method, the vinegar is put into bottles, which are 

 then well closed and placed in a vessel containing water. 

 The latter is then heated, and after it has boiled for some 

 time the bottles are taken out. Vinegar which has been 

 treated in this manner will, as Scheele states, keep indefinitely 

 without becoming turbid or spoilt. It is the same method 

 which is employed to this day. 



The first indication of the relation of micro-organisms to~\ 

 the diseases of fermented liquids, is found in Chaptal's work, 

 ' L'art de faire le vin,' which appeared in iSo/.f " There 

 is," he says, " a phenomenon which has not only attracted the 

 attention of numerous authors who have interested themselves 

 in the diseases of wine, but has also perplexed them. I 

 refer here to the films (les fleurs du vin) which develop in the 

 casks, and especially in the bottles, on the surface of the wine. 

 This film-formation always occurs prior to the wine becoming 

 sour, and foretells that this will take place. In my opinion, 

 it is a vegetation a byssus-growth which belongs to the 

 ferment-substance." We find here the conception of disease 

 connected with that of growth, but we can clearly place no 

 weight upon this ; it must be regarded more or less as an 

 isolated idea, a vague conception. At any rate, Chaptal's 

 statement had no appreciable effect on the progress of research, 

 and I have only mentioned it because it appears to contain the 

 first germ towards the assumption that the relation between 

 the diseases and micro-organisms is one of cause and effect. 



A practical application of Spallanzani's experiments, 

 similar to that of Scheele, was made by Appert at the 



* Carl Wilh. Scheele, Anmarkningar om sattet att conservera Attika (Kongl. 

 Vetenskaps Academiens nya Handlingar, torn. iii. Stockholm, 1782, p. 120. 

 Also in French (according to Pasteur) in Scheele's ' Memoires de Chimie,' Dijon, 

 1785. After Scheele's death, his works were published also in other languages. 



t My source in this case is Pasteur's * Etudes sur le vin,' as there is not a copy 

 of Chaptal's work in any of the public libraries at Copenhagen. 



