464 APPENDIX. 



and boil with alcohol. The acid gradually separates from the 

 alcoholic solution on cooling. It crystallises in oblique rhombic 

 prisms (F. P. 5, F. 3), is extremely glistening, and refracts 

 light strongly, loses no water of crystallisation at 100, but at a 

 higher temperature decomposes. It dissolves readily in water, is 

 insoluble in cold but dissolves in boiling alcohol, is insoluble in 

 ether, forms cry stalli sable salts with bases, and contains not only 

 carbon, hydrogen, and oxygen, but also nitrogen and sulphur. 



(21) Addition to p, 249, line 13 from bottom. Many organs 

 have a special tendency to accumulate large quantities of fat, 

 when in pathological states; hence it is especially necessary to 

 determine the normal quantities of fat which these organs contain. 

 We particularly refer to the liver, spleen, and kidneys. We do 

 not refer to those special fat-cells surrounded by connective 

 tissue, such as we find in the Folliculus adiposus cutis et renum ; 

 but we here find the fat specially accumulated in cells not very 

 unlike the ordinary epithelial cells. On making a microscopic 

 examination of the liver in its perfectly normal condition at a 

 certain period after a meal, it is very rarely that we find the 

 hepatic cells perfectly free from fat. In the spleen, which naturally 

 contains so large a number of colourless cells, we always find fat 

 both in the carnivora and herbivora. Frerichs* discovered fat in 

 the perfectly normal kidneys of dogs and cats, and von Hesslingf 

 constantly found it in the kidneys of fishes; and, finally, LangJ 

 has demonstrated its ordinary occurrence in the kidneys of cats 

 by microscopical and chemical investigations. In normal human 

 kidneys, Frerichs observed small quantities of fat, and Lang 

 found that fat was as often present as absent. Lang found from 

 1'8-g- to 3*9# of fat in the dried substance of the kidneys in cats, 

 but he was unable to detect the presence of this substance in the 

 kidneys of an ox or of a calf. It appears, both from pathological 

 observations as well as from these investigations of normal kid- 

 neys, that the fat principally occurs in the cortical substance, and 

 that it exists in the form of minute drops, which are partly free 

 and partly enclosed in the cells of the tubules. 



I must not omit to mention an observation which I have 

 repeatedly made. I have seen the " canaliculi contorti" of the 



* Die Bright'sche Nierenkrankheit u. deren Behandlung. Braunschweig, 

 1851, S. 43. 



t Histol. Beitr. z. Lehre v. d. Harnabsonderung. Jena. 1851, S. 52. 

 J De adipe in urina et renibus, diss. inaug. Dorpat, 1852, p. 48-64. 



