ITS AMOUNT OF WATER. 241 



that is to say, the conditions which give rise to a diminution of 

 the solid constituents of the serum, generally, at the same time, 

 also occasion a diminution of the coloured blood-cells. 



It is very difficult to ascertain whether copious draughts of 

 fluid occasion a temporary augmentation of the water in the serum, 

 in consequence of the rapidity with which an excess of water is 

 removed from the blood. Schultz* thought that he had convinced 

 himself by direct experiments on oxen, that the blood presented a 

 relative augmentation of water after the copious use of that 

 fluid ; Denis, on the other hand, denies that this is the case, at all 

 events in man. But that the solid constituents of the serum should 

 suffer diminution in the absence of proper nourishment, and that 

 there should thence be an augmentation of water, is only what 

 might be expected ; and is confirmed by all the investigations that 

 have been made either with healthy or diseased blood, when the 

 persons from whom it was taken had been deprived for a long time 

 of all nutriment, or had been only poorly and scantily fed. 



Since in the great majority of diseases comparatively little food 

 is taken in consequence of the loss of appetite or the prescription 

 of low diet, and the resorption of nutriment only proceeds imper- 

 fectly, or finally essentially nutritious matters are lost by 

 profuse excretions or by copious losses of the juices, (as for 

 instance, repeated blood-lettings), it follows, that in consequence 

 of the imperfect restitution of the substances which have been 

 normally or abnormally lost, the blood must become poor in solid 

 constituents. Hence the analyses of the blood in most diseases 

 show that it is specifically lighter, that is to say, poorer in solid 

 constituents, than normal blood. This poorness of the blood in 

 solid constituents is not, as a general rule, associated with a 

 diminution of the collective mass or volume of the blood circulating 

 in the vessels ; for in our consideration of the mechanical meta- 

 morphosis of matter, we shall be led to the result, that the 

 blood has a constant tendency to retain its original volume, so long 

 as the whole mechanism is not disturbed. Hence if solid sub- 

 stances are abstracted from the blood in disease, and are not again 

 replaced, this fluid not only appears watery, in consequence of its 

 containing less solid constituents, but also from its having taken 

 up more water than it contains in the normal state. In such cases 

 the quantity of water is not only relatively, but absolutely increased 

 in the blood. Even in the beginning of most diseases, especially 

 those of an acute character, we find the blood more watery than 



* Hufeland's Journ. 1838. H. 4, S. 291. 

 VOL. II. R 



