To the metallic element in the corpuscles has been somewhat fancifully attributed an electrical and a polarizing action, and even a power of increasing heat by mechanical friction! There is a general and better-founded opinion that it greatly aids in the conveyance of oxygen and in oxidation (a main function of the corpuscles), and some modern researches support this opinion - thus, Schonbein, quoted by Dr. A. Sasse, proved that animals without blood-corpuscles were suffocated in oxygen as much as others in nitrogen; that the gas must become changed into ozone and antozone in order to be fully efficient, and that iron, or corpuscles, will effect this change. Iodized paper is turned blue both by ferric solutions and by diluted blood, and peroxide of iron can change into protoxide and ozone. As an illustration, he quotes the spread of rust on steel, or "iron mould" on linen, the stain extending by formation of ozone, which corrodes the adjacent particles of the steel, while the reduced oxide attracts fresh oxygen from the air. Similarly, it is argued, the iron in the corpuscle continues alternately to attract and to give up oxygen, and to become a proto- or a per-salt until finally excreted (Schmidt's Jahrb., v., 1865).

If iron, when taken into the system, does aid oxidation it should raise the temperature and increase tissue-change, but the amount of scientific evidence on the subject is unfortunately small. The observations of W. Pokrowsky, though valuable and often quoted, were made on patients seriously ill and recently removed to hospitals, and seem scarcely sufficient for the conclusions drawn from them. In five out of six cases the temperature was slightly raised; in one (a case of phthisis with haemoptysis, taking small doses of tinctura ferri) it was lowered; the pulse was either changed or slightly increased, the elimination of urea was augmented, and weight was gained. In one case the rise of temperature followed within five hours of the dose, and it occurred equally in the cases where temperature was previously normal. It should be noted that the syrup of iodide of iron was chiefly used, and the iodine must be allowed for as influencing tissue-change; also that Pokrowsky himself, while recording improved nutrition, traces it only to "improved tone of capillary vessels," not to increased oxidation (Virchow's Archiv, Bd. xxii., v. 6); he states that he acted as a student under Dr. Botkin. I find no reference to other observations by the latter upon healthy men, as mentioned by Sasse.

Some recent analyses by Rabuteau would seem to support the supposition of increased oxidation, but they refer only to the renal secretion; comparing the results of five days when taking daily 12 ctgr. of perchlo-ride of iron with the same period, on the same diet, but without the iron, he concluded that it did not affect the quantity of his urine, but augmented its acidity and its solid constituents and urea (10 per cent.). Phosphoric acid was lessened, as it usually is, under cod-liver oil and other restoratives.

The researches of Picard (v. p. 143) proving a definite ratio between the amount of iron and of oxygen contained in the blood, are of importance in this connection, and it is an axiom that iron preparations exert their best curative effect when the supply of oxygen is ample; but the conclusion of Sasse - that iron can supply the place of red corpuscles as an ozonizing agent in the body can scarcely be correct; were it so, the cure of anaemia and chlorosis would be more certain than it is. We can but consider iron as an adjuvant, and as being, when in the corpuscles, subject to other than merely chemical laws.