REPORT ON ANIMAL PHYSIOLOGY. 123 



First Second 



Chlorure of sodium ") Analysis. Analysis. 



— potassiuni. 



Subcarbonate, "j )- 8-370 7-304 



Phosphate, ... >alkaline.. 



irbonate, ") 

 )hate, ... >a 

 late, J 



Sulphate, 



Subcarbonate of lime 1 



' magnesia 



Phosphate of lime [ 9. inn 



magnesia... f 



1-414 



iron 



Peroxide of iron J 



Loss 2-400 2-586 



1000-000 1000-000 



" Doubtless under various modes of applying heat, alcohol, 

 the subcarbonates, &c., to the blood, many substances may be 

 made to appear, which are but variations of its essential compo- 

 nents — (albumen, fibrin, and cruor) . The knowledge of these 

 may enrich animal chemistry, if the object were only to compre- 

 hend, comparatively and in the gross, the series of changes which 

 any matter may undergo under different agencies, and not to 

 discover new materials and declare them to be real components 

 of the organic body. Tiedemann reckons the peculiar matter 

 of saliva amongst the components of the blood ; and lately urea 

 has been coimted amongst the number, because it has been fovmd 

 in the blood after extirpation of the kidneys. Incontestibly, in 

 cei'tain cases of suppressed secretion or of inci'eased resorption, 

 bile, the seminal fluid, &c., have been found there ; but no special 

 product of secretion can yet, on sufficient gi-ounds, be proved to 

 be a normal component of the blood, and from what we know of 

 it, such a result is not to be expected*." Numerous colouring 

 matters have been classed amongst the components of the blood, 

 from the explanations of chemists respecting the causes of co- 

 lour — as globulin, erythragin, &c. Burdach thinks that they are 

 either the product of reagents acknowledged not to exist in the 

 blood, or are modifications of albumen. Boudet, by treating very 

 large quantities of blood, contends that all blood contains cho- 

 lesterinf. 



Gas. — Under the air-pump, air has been observed to escape 

 from recent blood ; its quantity has been variously computed. 

 Most observers, as Sir Humphry Davy, Brande, Scudamore, Vogel, 

 state that it is carbonic acid. The quantity is very variously esti- 

 mated. Brande obtained two cubic inches from eight ounces of 



* Burdach, iv. 68. 



t Annales de Chimie et de Physique, torn. Hi. p. 342. 



