84 Iron contained in Blood. [Book IX. 



marine fait, chalk of foda, and calcareous phofphat ; 

 thi^ laft appears to produce the rofe-coloured precipi- 

 tate, obtained by pouring the nitrous folution of mer- 

 cury into ferum. Though the liquid is fcarcely co- 

 loured, the addition of nitrous acid, and more efpeci- 

 ally of mercurial nitre, produces a rofe or light fiefh- 

 colour, which M. Fourcroy has often obferved in many 

 other animal liquors. 



The crailamentum, when well warned in water, is 

 feparated into two very dillinct fubftances, one of 

 which is diflblved, and tinges the water of a red co- 

 lour, while the other remains behind in the ftate of a 

 white fibrous matter, the fame as that which adheres 

 to the ftirrer with which recent blood has been agitated, 

 in order to prevent its coagulation. The water in 

 which the red part is diflblved, when heated with 

 different menflrua, exhibits all the characters, of ferum ; 

 but it contains a much greater quantity of iron, which 

 may be obtained by the incineration of the coal, and 

 fubfequcnt warning to feparate the faline matters. 

 The refidue of this wafliing is a yellow calx of iron, 

 of a beautiful colour, and ufually attracted by the 

 magnet. The red colour of the blood is therefore 

 with fome appearance of reafon attributed to this metal. 

 Iron has been obtained from the blood in confiderable 

 quantity by Menghini, Rpueile, and Bucquet. 



The lame chemifts found that iron was capable of 

 pa fling into the blood from the inteftines, fince patients 

 \vho were under a courfe of martial medicines are 

 known todifcharge a part of it by the urinary paflages. 

 Iron is obtained from the red particles of the blood, 

 but not from the warned eoagulum. Thefe facts, to- 

 gether with the increafed rednefs of the blood by 

 palling through the lungs, where it may be fuppofed 

 to iiifrcr a degree of calcination from the abibrption 



of 



