ITS PHYSICAL, CHEMICAL, AND STRUCTURAL CHARACTERS. 177 



of oleaginous matter with the food. There are few ordinary meals, however, 

 from which such matter is altogether excluded. When such milky serum is 

 examined with the Microscope, the opacity is found to be due to the presence 

 of an immense number of exceedingly minute granules, resembling in appearance 

 those which form the " molecular base" of the chyle. They seem to be com- 

 posed of two chemically distinct substances; for when the milky serum is agi- 

 tated with ether, a part is dissolved, whilst another portion remains suspended; 

 and this latter is soluble in caustic potass. The former, therefore, appears to 

 be identical with the "molecular base" of the Chyle, and to be of an oily or fatty 

 nature; whilst the latter belongs to the proteine compounds. The Crassa- 

 mentum of such blood often exhibits a pellucid fibrinous crust, sometimes inter- 

 spersed with white dots ; and this seems to consist of an imperfectly-assimilated 

 proteine compound, analogous to that found in the serum. The quantity of this 

 varies according to the amount of the proteine compounds present in the food. 

 The presence of saccharine matter in the blood (in which it forms part of the 

 " extractive"), after the ingestion of a large quantity of saccharine or farina- 

 ceous aliment, has been noticed by many experimenters. It might be fairly 

 presumed that a temporary augmentation must take place in the aqueous con- 

 stituent of the blood, whenever any considerable quantity of liquid is ingested ; 

 and yet this augmentation is probably much less considerable, under ordinary 

 circumstances, than we should at first be inclined to suppose. For there exist 

 various provisions in the system (the peculiar Malpighian apparatus of the 

 kidneys being the chief) for rapidly freeing the blood from any superfluity of 

 water ; and thus any excess of fluid absorbed is speedily drawn off again. But 

 further, there is evidence that, when the vessels are already filled, absorption 

 does not take place with nearly the same readiness as after long abstinence from 

 liquids ; the rate of absorption being in great degree governed by that at which 

 the liquid is disposed of. It follows, therefore, that the absorption of even a 

 considerable amount of water within a short time, need not really involve any 

 great dilution of the blood ; and it is probable that a considerable previous 

 reduction of its density will only take place in a state of health, when it has 

 first undergone an unusual elevation, in consequence of the removal of part of 

 its water by perspiration, diuresis, &c., without a corresponding replacement of 

 it by absorption. It has been affirmed, however, that when Oxen have taken 

 immense draughts of water, the blood has been so much diluted, that some of 

 the corpuscles have burst ( 139) and the coloring matter has passed out of the 

 body; whilst, on the other hand, it has been found that when two dogs had 

 been kept for some weeks on the same kind of food, but one was not allowed to 

 drink, whilst the other was made to take a large quantity of water, the specific 

 gravity of the blood was nearly the same in each. 1 The influence of the regimen 

 upon the composition of the blood, however, appears to be more definite and 

 constant. An animal diet tends to increase the whole amount of solid matter, 

 but especially to augment the proportion of corpuscles. On the other hand, a 

 vegetable diet tends to lower the whole amount of solid matter, occasioning a 

 marked reduction in the corpuscles, whilst it seems rather to increase the albu- 

 men ; thus showing that the decrease in the corpuscles is not due to a deficiency 

 in their azotized pabulum, but depends on some other condition. The develop- 

 ment of fibrin appears to take place at least as readily on the vegetable as on 

 the animal regimen. Hence we see what may, and what may not, be effected 

 in the treatment of disease, by the adoption of a particular dietetic system, for 

 we may promote or retard the development of the red corpuscles, by the employ- 

 ment of an animal or a vegetable regimen, but can make little or no impression 



1 Dr. Bence Jones, in "Medical Times," Aug. 2, 1851, p. 115. 

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