The most extended investigations to deter mine the therapeutic value of vanadium were made by Laran Medical' xc, 1899). His experiments upon animals were made with guinea pigs, frogs, rabbits and dogs and he used a 5 per cent watery solution of meta vanadate of soda with a sufficient quantity of physiological salt solution added. The conclu sions at which he arrived after a very exhaust ive consideration of the subject were as fol lows: 1 Vanadium compounds oxidize very readily and hence are of great value in the industrial arts.
2 Metavanadate of soda is very poisonous.
3 This salt has very little effect, in vitro, upon the digestive fluids, blood sugar, yeast and microbes.
4 In spite of its toxicity it can be given to human beings, by mouth, in doses of one to five milligrams, during the 24 hours. It is desirable to intermit its administration for two or three days during the week. It is a tasteless sub stance, but is easily tolerated when it is given in the manner which was indicated above.
5 It almost always increases the appetite, the strength and the weight.
6 The urine is slightly increased by its use, there is also an increase in the urea and in the coefficient of nitrogen oxidation. In dia betes it will lessen the formation, but only temporarily.
7 It stimulates the process of internal com bustion and causes constant change in the blood by oxidation, the formation of vanadic acid being followed by that of hypovanadin, the latter being, therefore, an acid bearer to the tissues.
8 Metavanadate of soda has a certain value as a therapeutic agent, its action being similar to that of arsenic.
It could, therefore be properly recommended to those who are sukering with poor nutrition or with various constitutional troubles, includ ing tuberculosis, chlorosis, rheumatism, soften ing of the arteries and enlargement of the veins.
Poisonous effects may be produced by its absorption when used medicinally, when taken accidentally or when exposed to its vapors, the latter occurring frequently to those who are workers in vanadium. The lesions which re sult from poisoning with vanadium are to be found chiefly in the lungs, the kidneys and the gastrointestinal tract.
Those whose employment constantly exposes them to the influence of vanadium are frequent sufferers with tuberculosis in a form which dispose them to the occurrence of severe or even fatal haemorrhage. Such workers also suffer constantly with irritation of the nose, throat and eyes. See MINERAL PRODUCTION OF