268 BLOOD. 



that arthritic blood is distinguished by the presence of uric acid 

 and urea (Garrod*). 



The immediate effect of the inhalation of ether seems to make 

 the blood richer in water, poorer in blood-corpuscles, and strik- 

 ingly rich in fat (Lassaigne,f v. Gorup-Besanez J). According to 

 the numerous investigations of Gorup-Besanez, no distinct rela- 

 tion can be discovered between the bruit in the jugular veins and 

 the chemical constitution of the blood. This sound may exist 

 where there is an increase of all, or of some only of the solid 

 constituents of the blood, or where they are diminished, or, finally, 

 where there is a perfectly normal composition of the blood. 



The quantity of blood contained in the living body has never 

 been accurately determined, for the simple reason that the entire 

 mass of the blood cannot be completely removed from the vessels 

 and weighed; hence the determination can only be made approxi- 

 mately by indirect methods. Herbst endeavoured to calculate 

 the quantity of blood in the vessels by the quantity required for 

 the complete injection of the veins and arteries. But all who 

 have made injections, or even carefully examined the injected 

 subject, must feel that the estimate will be very uncertain when 

 based upon such methods. Vogel,|| Dumas,1f and Weisz,** have 

 proposed but not practised other methods of determination. 

 Valentinft suggested the ingenious expedient of abstracting blood 

 from an animal, whose weight was known, and after determining 

 the solid constituents, immediately injecting a certain quantity of 

 pure water into the veins, and then again taking blood and 

 examining the solid residue with the greatest care. From the 

 difference in the amount of the solid constituents in the two dif- 

 ferent kinds of blood, Valentin calculated the ratio of the weight 

 of the whole blood to that of the body in dogs and sheep as 1 : 4| 

 in the former, and 1 : 5 in the latter. This method would afford 

 sufficient accuracy if the walls of the blood-vessels were not more 

 easily permeated by a thin than by a dense plasma, if the whole 

 mass of the juices in respect to the amount of water did not stand 



* London Medical Gazette. Vol. 31, p. 88. 

 f Gaz. M^d. de Paris. No. 11, 1847. 

 j Arch. f. physiol. Heilk. Bd. 8, S. 515 -- 523. 

 Ibid. p. 532543. 



II Patliol. Anat. des menschl. Korpers. Leipz. 1845, S. 59 [or English trans- 

 lation, p. 84]. 



^f Chira physiol. et me'd. Paris, 1848, p. 326. 

 ** Zeitschr. d. k. k. Gesellsch. d. Aertze. Dec. 1847, S. 203229. 

 tt Repert. der Physiol. Bd. 3, S. 281293. 



