There can be no doubt that, for those who can stand it in large quantities, milk is an excellent aid in the fight against old age and in its treatment. As most constituents of the blood enter the milk, perhaps it is not too daring to say that drinking milk is, in a measure, drinking blood. Evidently blood contains all the internal secretions of the ductless glands as well as most valuable ferments; hence the rational prevention and treatment of old age would consist in drinking blood. There is, however, no general tendency to such bloodthirsty methods at the present time, but, maybe, it will be used in the future. But if we cannot drink blood let us drink milk, the most valuable food there is. ------------------------------------------------------------------------ CHAPTER XL. ON BLOOD AS AN ARTICLE OF FOOD CONTAINING IRON AND ANIMAL EXTRACTS—SAUSAGES AND BLOOD PUDDINGS. IRON is a most important element of our blood, the lack of which, as in chlorosis and various anæmic conditions, may produce very serious symptoms. To replace this deficiency iron is introduced into our system, and this can be done in two ways: either by the natural way, i.e., by food which contains iron, or artificially, by means of drugs which contain iron. It is the opinion of Bunge that iron, given in drugs, especially as inorganic iron, is not so readily absorbed and assimilated as organic iron, i.e., iron as it occurs in various articles of food, and especially in the blood. Therefore an effort has been made with more or less success by manufacturing chemists to make preparations of iron obtained from the blood, and Professor Bunge[299] has experimented on animals by using iron containing nuclein, separated from the yolk of eggs; and in Professor Kossel’s laboratory such a preparation has been made from the eggs of the carp. It was found that these preparations were perfectly absorbed and assimilated. Footnote 299: Bunge: Lehrbuch der Physiologie, Berlin, 1907. Professor Bunge, and also his pupils Abderhalden and Haüsermann, found that all animals which received food containing but little iron, became anæmic, e.g., young rabbits fed only on milk, which, as above mentioned, is very poor in iron. Later food was given that contained iron (as green vegetables, cabbage, herbs, etc.; or meat, yolks of eggs, and fruit), and soon afterward the iron contents of their blood was found to be increased. Even if we are not anæmic or chlorotic, it is necessary to take a certain amount of iron, preferably organic iron, into our systems.