ADDITIONS AND NOTES TO VOL. II. 537 



acid found by Schottin in the sweat is produced from the decom- 

 position of hippuric acid by the sweat, or whether the acid is 

 separated unchanged by the sweat-glands without being previously 

 converted into hippuric acid (as when it is separated by the urine). 

 As cinnamic acid would appear from the discovery of Marchand 

 and Erdmann to be separated by the kidneys as hippuric acid, 

 this question might apparently be determined by an examination 

 of the acid that appears in the sweat after the use of cinnamic 

 acid ; for if, instead of the latter, benzoic acid should appear, it 

 would tend in some degree to favour the opinion that the cinnamic 

 acid was first converted into hippuric acid, from which the 

 benzoic acid was then produced. If, on the other hand, cinnamic 

 acid were found in the sweat, it would afford greater probability 

 to the view, that the benzoic acid found in the sweat could not 

 have been converted into hippuric acid before its excretion. 

 Unfortunately, however, the quantity found in Schottin's experi- 

 ments was no more than sufficient for a microscopico-chemical 

 examination, but the microscope could not settle this point 

 definitely, owing to the great resemblance between the crystalline 

 form of these two free acids and of their salts, G. E. D.] 



(42) Addition to p. 400, line 2. We must, however, observe 

 that the extractive matters occur in very variable quantities in the 

 urine, more especially during disease, although it may also be the 

 case in health during different physiological relations. Thus, for 

 instance, Scherer* found that children, in relation to their bodily 

 weight, excrete far more extractive matter through the urine in 

 24 hours than adults. He found that the sum of the excretion 

 was 0*346 of a gramme in the 24 hours for every kilogramme's 

 weight of a child, while in the case of an adult it was only 0*156 

 of a gramme for every kilogramme's weight. Scherer, moreover, 

 made a very remarkable observation on an insane person, who, 

 although he had scarcely taken any nourishment for four weeks, 

 yet discharged a large quantity of extractive matters, exceeding 

 even the amount of the urea ; thus, for instance, he excreted 9*48 

 grammes of urea and 10*59 grammes of extractive matters in the 

 24 hours. 



(43) Addition to p. 400, 2 lines from the bottom. Hegarf 



* Verhandl. d. pliys.-raed. Ges zu Wurzburg. Bd. 3, S. 187-190. 

 t Ueber die Ausscheidung der OhlorverbindiiDgcn durch den Harn. 

 Inauguralabli. d. nied. Fac. zu Giessen vorgel. 1852. 



