100 THE LACTIC ACID GROUP. 



in their urine ; and why, finally, in most febrile diseases, lactic 

 acid may be recognised in the urine. 



The details of these investigations, which will be given in 

 another place, afford numerous confirmations of the experiments 

 which I formerly instituted on the urine.* Berzeliusfj during his 

 later years, entertained no doubt regarding the correctness of the 

 results which he had so long before obtained in reference to the 

 presence of lactic acid in the urine. BoussingaultJ has quite 

 recently found lactic acid in the urine of pigs fed with potatoes, as 

 well as in that of cows and horses. (In the urine of the horse he 

 found 1-128$ of lactate of potash, and 0'881 of lactate of soda.) 



In accordance with this view is the almost universal occurrence 

 of lactic acid in urine containing a considerable quantity of oxalate 

 of lime, so that by a microscopic examination of a specimen of urine, 

 a conclusion may often be drawn regarding the presence or absence 

 of lactic acid. Hence in those diseases in which there is an increase 

 in the amount of oxalate of lime, as in pulmonary emphysema, 

 disturbances of the nervous system, rachitis, &c., lactic acid is 

 always associated with this salt. Scherer and Marchand|| have 

 sometimes observed a considerable augmentation of lactic acid in 

 the urine in rachitic children, and I have also noticed it in the 

 osteomalacia of adults. 



In determining the presence of lactic acid we must always 

 employ fresh urine, if we wish to draw any conclusion regarding 

 the composition of the renal secretion. The admirable investi- 

 gations of Scherer^[ regarding urinous fermentation, were the 

 first to direct attention to the circumstance that there is a gradual 

 augmentation of the free acid, when the urine is exposed to the 

 atmosphere. The lactic acid must then be formed from some 

 unknown matter, probably from what we term an extractive 

 matter. I** had formerly observed something similar occur in 

 diabetic urine, since, when freshly passed, I always found it neutral, 

 although subsequently it became acid ; in consequence, however, 



* Journ. f. prakt. Ch. Bd. 25, S, 1, and Bd. 27, 8. 257; Handworterb. d. Phy- 

 siol. Bd. 2, S. 10. 



t Jahresber. Bd. 27, S. 590. 



Z Ann. de Chim. et de Phys. 3 S6r. T. 15, p. 97-114. 



Untersuclmngen z. Pathol. S. 74 ff. 



|| Lehrbuch d. phys. Ch. S. 105. 



U Ann. d. Ch. u. Pharm. Bd. 42, S. 171 ; andUnters. z. Pathol. S. 1-16. 



** De urina diabetica. Diss. inaug. Lips. 1835. 



