FATS. 267 



cal elements, who shows that the cloudy turbidity of the chyle which 

 depends on the presence of the fat, disappears in proportion as 

 the isolated granules, the aggregated granules, and the cells are 

 developed. The serum of pus moreover contains much less fat 

 than pus-corpuscles. In the blood we find that fat is especially 

 deposited in the cells and in the fibrin, the granular contents of 

 many of the blood-corpuscles consisting of this substance. All 

 plastic exudations contain more fat than the non-plastic ; for the 

 latter, as dropsical fluids and tubercular masses, although occa- 

 sionally containing much cholesterin, usually contain very little 

 true fat; while on the other hand exuberant, highly cellular 

 cancers abound in this ingredient. 



In pus, the pus-corpuscles often sink some lines below the 

 level of the fluid; on comparing the amount of fat in the 

 supernatant serum with that in the pus beneath it in which the 

 corpuscles were suspended, I observed, in two experiments con- 

 ducted with different pus, that in one there was only 7*13^ of fat 

 in the solid residue of the serum (which should have contained most 

 of the fat since it was taken from the surface of the pus after it had 

 stood a long time,) while the thick purulent sediment contained 

 18*4 1; in the other case there was 9'084^ in the residue of the 

 serum, and 17'14 in that of the pus. The difference between the 

 amount of fat in the serum of the pus and in the pus-corpuscles 

 is most plainly apparent when both the sediment and the serum 

 of good pus are suffered to remain in well closed vessels. Both 

 fluids become acid, and fats and fatty acids are separated from 

 them; in the former these changes are but slightly developed, 

 whilst the acid purulent sediment exhibits, under the microscope, an 

 innumerable quantity of the most beautiful crystallisations of mar- 

 garic acid and of margarin, with cholesterin. 



The fats of the blood are also principally deposited in the cells 

 or blood-corpuscles. I found in 100 parts of well dried blood- 

 corpuscles taken from the blood of the ox, and whose mode of 

 preparation I shall explain in the second volume of this work, 

 2-214% of fat in one experiment, and 2'284 in another; the 

 fibrin of the same blood contained in the one instance 3*2 18, in 

 the other 3'189 of fat; while 100 parts of the solid residue of 

 the serum yielded 1-821, and 1'791 parts of fat. The blood- 

 corpuscles have, unfortunately, scarcely ever been examined with 

 reference to their amount of fat ; in other respects, however, a 

 comparison with the analyses instituted by other observers on the 

 blood, leads to the same result. 



