ITS PHYSICAL, CHEMICAL, AND STRUCTURAL CHARACTERS. 255 



to 5 parts of lead, 0.5 to 2.5 parts of copper, and from 10 to 24 parts of 



manganese. 1 



188. 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 notwithstand- 

 ing the want of absolute correctness in the analyses of which we are at pres- 

 ent iu possession, those that are made by similar methods give results suffi- 

 ciently trustworthy to enable them to be compared together, and thus to 

 give a tolerably correct indication of the circumstances which determine the 

 increase or diminution iu the principal components of the Blood. The first 

 of these modifying conditions which requires special notice is Aye. During 

 the latter part of foetal life, the blood is remarkably rich in solid contents, 

 as appears from the following comparative analyses of Denis : 2 



Venous Blood of Blood of Umbilical 



Mother. Artery. 3 



Water, 781 701.5 



Solid constituents, . . 219.0 298 5 



The larger quantity of solid constituents in the blood of the foetus is chiefly 

 due to the increased proportion of corpuscles, which appears to continue for 

 a short time after birth ; but it gradully diminishes ; and the whole amount 

 of solid matter iu the blood seems to fall to its lowest point during the period 

 of childhood. Towards the epoch of puberty, however, the amount of solid 

 matter increases again, the chief augmentation being in the corpuscles; and 

 it remains at a high standard during the most vigorous period of adult life, 

 after which it begins to decline. This is made apparent in the following 

 table, deduced from the analyses of Denis, which are confirmed by those of 

 Lecauu and Simon : 4 



Solid Constituents. 



In 5 individuals between 5 months and 10 years, . . 170 



13 " " 10 years and 20 " . . 200 



11 " 20 " 30 " . . 240 



12' " " 30 " 40 " . . 240 



6 " " 40 " 50 " . . 240 



8 " 50 " 60 " . 220 



9 " 60 " 70 " . . 210 



189. An appreciable difference exists between the blood of the two Sexes; 

 that of the male being from 12 to 20 per cent, richer in solid contents than 

 that of the female, the excess being particularly observable in the propor- 

 tion of the corpuscles. There is no doubt, also, that the proportions of the 

 constituents vary considerably with individual temperament and constitution ; 

 the proportion of the whole solid constituents, and especially of the cor- 

 puscles, being considerably greater in individuals of the plethoric or " san- 

 guineous" temperament than in persons of the "lymphatic" temperament; 

 and it appears from the analyses of Lecinu, 5 that the sexual difference in 



1 Melsens (Annal. de C. et de P., xxiii, p. 358) denies the presence of copper and 

 lead; and Bechamp (Journ. de la Phys., I860, vol. iii, p. 211) appears to think the 

 occurrence of all or any of these metals to be merely accidental. 



2 Recherches Experimentales sur le Sang humain,and Simon's Animal Chemistry, 

 vol. i, p. 238; see also Pamim, Virchow's Archiv, 1864, Bd. xxix, p. 481. 



3 Which has been shown by Poggiale to be identical with that of the body of the 

 Fcetus (Comptes Renclus, t. xxv, p. 198). 



4 Animal Chemistry, vol. i, pp. 237-239. 



5 Etudes Chimiques sur le Sang huimiin, p. 66, and Simon's Animal Chemistry, 

 vol. i, p. 236. 



