18S CHEMICAL RESEARCHES ON THE ANIMAL FLUIDS. 



wide a field, and one not immediately connected with the ob- 

 jects of this society : the subject, however, appears important. 

 So employed It is not a little remarkable, that blood is used by the Arme- 

 ni^ns.^ '^™^' "'^" dyers, together with madder, in the preparation of their 

 finest and most durable reds*, and that it has even been found 

 a necessary addition to insure the permanency of the colour)-. 

 This fact alone may be regarded as demonstrating the non- 

 existence of iron as the colouring principle of the blood, for the 

 compounds of that metal convert the red madder to gray and 

 black. 

 Menstrual While engaged in examining the colouring matter of the 



^"^<^« blood, I received from Mr. William Money, house surgeon to 



the general hospital at Northampton, some menstruous dis- 

 charge, collected from a woman with prolapsus uteri, and 

 consequently perfectly free from admixture of other secre- 

 tions. It had the properties of a very concentrated solution of 

 the colouring matter of the blood in a diluted serum, and 

 afforded an excellent opportunity of corroborating the facts 

 respecting this principle, which have been detailed in the pre- 

 ceding pages. Although I could detect no traces of iron, by 

 the usual modes of analysis, minute portions of that metal 

 may, and probably do exist in it, as well as in the other animal 

 fluids which I have examined j but the abundance of colouring 

 matter in this secretion should have afforded a proportional 

 quantity of iron, did any connection exist between them. It 

 has been observed, that the artificial solutions of the colouring 

 matter of the blood, invariably exhibit a green tint when 

 viewed by transmitted light : this peculiarity is remarkably dis- 

 tinct in the menstruous discharge;. 

 Rapid repro- ^ hope that some of the facts furnished by the above expe- 

 iiuction of per- riments may prove useful to the physiological inquirer: they 

 tect blood. account for the rapid reproduction of perfect blood after very 

 copious bleedings, which is quite inexplicable upon that hypo- 

 thesis which regards iron as the colouring matter, and may 



» Tooke's Russian Empire, Vol. Ill, p. 497. 

 •j-Alkin's Dictionary, Art. Dying, and Philos. Magazine, Vol. XVIII. 

 \ I could discover no globules in this fluid ; and although a very slight 

 degree of putrefaction had commenced in it, yet the globules observed 

 in the blood would not have been destroyed by so trifling a chauge. 

 4 perhaps 



