0* 



VII7ERSITT 



PREFACE. 



IT is quite unnecessary here to enlarge upon the prominence 

 and the commercial value of the products of the various branches 

 of industry treated of in this volume, since they are indispensable 

 requisites as well in domestic economy as in the arts. But not- 

 withstanding the great importance of .these subjects, little reliable 

 information in regard to them is found in our technical literature, 

 and that little is so widely scattered as to make it almost inac- 

 cessible to most manufacturers. 



Of all the branches of industry based upon chemical processes, 

 the manufacture of vinegar has made the least progress, and con- 

 sequently disturbances and large losses of material are here of 

 much more frequent occurrence than in other fermenting indus- 

 tries which are carried on in accordance with established rules, 

 whose correctness has been ascertained by many experiments. 



With few exceptions there are no works in the English lan- 

 guage in which an attempt has been made to establish the manu- 

 facture of vinegar upon a rational basis, and in accordance with 

 the laws of nature as regards the chemical as well as the physi- 

 cal processes. To attain this object as nearly as possible has 

 been the aim in the preparation of the portion of this volume 

 relating to vinegar. Since the physical processes, especially the 

 exact maintenance of determined temperatures and the production 



