174 



OF THE BLOOD. 



genetic substances, which are undergoing progressive metamorphoses, such as 

 the peculiar soluble compounds which are considered by Mulder as the binoxide 

 and tritoxide of protein ( 30) ; or non-azotized alimentary matters, or products 

 of the retrograde metamorphoses of the tissues, which are on their way to the 

 excretory organs, as is the case with the sugar, urea, uric hippuric acids, crea- 

 tine and creatinine, 1 which have been detected in it in minute proportion. It 

 can scarcely be doubted that the more attentive study of this part of the blood 

 will be attended with the discovery of many facts that would throw great light 

 upon the Chemistry of the histogenetic operations, and of the retrograde meta- 

 morphoses of the effete materials of the tissues. 



157. The list of the Inorganic Constituents of the Blood, which is given in 

 the preceding table ( 154), does not express the mode in which they 'are 

 grouped together ; and it takes no account of the Carbonic acid, which certainly 

 exists in the blood united with Alkaline bases ( 83). The proportion which 

 the Carbonates bear to the Phosphates, however, seems to be small in Human 

 blood ; as is shown by the following table, founded on the analysis of Verdeil, 2 

 of the per-centage c&mposition of the ash of the blood, after deducting the car- 

 bon still contained in it. The corresponding analyses of the blood of the Dog, 

 Ox, Sheep, and Pig, are here given, to show the remarkable variation between 

 the relative amounts of the Carbonates and Phosphates, in the blood of Herbi- 

 vorous and Carnivorous animals, of which mention has already been made ( 84). 

 It will be observed that the proportion of Chloride of Sodium exhibits a remark- 

 able constancy. 



158. We have now to inquire into the principal modifications, which the 

 relative proportions of these constituents undergo in the state of health, under 

 the influence of varying conditions of the system; and, notwithstanding the 

 want of absolute correctness in the analyses of which we are at present in pos- 

 session, those that are made by similar methods give results sufficiently trust- 

 worthy to enable them to be compared together, and thus to give a tolerably 

 correct indication of the circumstances which determine the increase or diminu- 

 tion in the principal components of the Blood. The first of these modifying 

 conditions which requires special notice is Age. During the latter part of foatal 



1 The discovery of the presence of these two substances in the blood of oxen has recently 

 been made by MM. Verdeil and Dolfuss, who have operated upon very large quantities of 

 the fluid. (See M. Board's "Cours de Physiologic," torn. iii. p. 95.) 

 "Ann. der Chem. und Pharm.," band Ixix. p. 89. 



3 Man, forty-five years old, suffering from weak digestion. 



4 Woman, twenty-two years old, sanguineous temperament. 

 6 After a flesh diet of eighteen days. 



6 After feeding for twenty days upon bread and potatoes. 



