248 HALOIDS AND HALOID BASES. 



have been too hastily led, by imperfect experiments, to form 

 theories regarding the fatty degeneration of cells and tissues. 



Physiological Relations. 



Occurrence. Fats occur, not only in the animal world, but also 

 in vegetables, especially in seeds and the kernels of fruits, from 

 which we chiefly obtain the fatty oils and certain butter-like fats, 

 as for instance, cacao butter, palm oil, &c. Fats have been found 

 in almost all parts of all animals, and it is only in the lowest classes 

 of animals that fat is entirely absent. It is in the higher organ- 

 isms that we find most fat, where it exists as a mixture of the 

 above-named salts of oxide of lipyl, and is deposited in the 

 cellular tissue in oval or polyhedric cells. 



It is very rarely that we find one of the above-named fats 

 unmixed with the others, and in the few cases of this nature which 

 have been observed, the character of the fat has been recognised 

 by the microscope only, and not by chemical means; thus C. 

 Schmidt (according to Bergmann*) and Vogt-f- found distinct 

 crystals of stearin in the ovum of the frog, and of the accoucheur 

 toad, (Bufo obstetricans,) and I have frequently, although not 

 invariably, found delicate masses of acicular crystals in the albumen 

 of eggs that had been sat upon from three to six days, which from 

 the few tests that I could attempt, seemed to consist of margarin. 



When we consider the occurrence of fat in the different parts 

 of the human body in a normal condition, we, in the first place, 

 discover large accumulations of fat, which, when constituting an 

 integral constituent of certain organs, rarely disappear entirely, 

 even in the latest stages of wasting diseases ; in the next place we 

 observe, that there are parts of the body in which the quantity of 

 fat varies considerably, being either extraordinarily small or very 

 large ; and finally, that there are some organs in which accumula- 

 tions of fat are of very rare occurrence. The orbit of the eye and 

 the heart appear to be the most constant seats of fat, for although 

 we observe that the fatty matters surrounding the different parts of 

 the eye diminish in all forms of disease, causing the eye-ball to 

 sink in the orbit, the socket of the eye is never found entirely free 

 from fat. A similar remark applies to the fat surrounding the 

 heart, and penetrating between its bundles of fibres ; and it would 

 likewise appear that fat is never entirely absent from the muscles 



* Muller's Arch. 1841. S. 89. 



t Entwickelung der Geburtshelferkrotc. Solothurn. 1842. Einl. 



