572 SALT AND ITS PHYSIOLOGICAL USES. 



finding this modicum. It is exceeded by the quantities normally exist- 

 ing in natural foods. The difficulty, then, is not in obtaining- the 

 nutritive substances which contain this modicum; it would rather be 

 in devising a food sufficient in other respects, that is to say, as regards 

 nitrogenous, fatty, and starchy matters, in which this modicum did 

 not exist. 



Nevertheless a physiologist, Forster, in 1N64, was aide to do this. 

 He utilized the waste from meat powder derived from the manu- 

 facture of Liebig's extract, treating it several times with boiling 

 water, so as to wash away almost all the soluble salts. With this 

 leached meat, together with starch and fat, he formed a ration in which 

 there was wanting nothing but the mineral salts/' 



Animals nourished with this ration in reality suffered from mineral 

 inanition. The experiment of Forster, carried out at Munich under 

 the direction of Voit, is. in fact, a typical one of this kind and perhaps 

 the only one performed until latterly, when Bunge and other physi- 

 ologists took up the matter again. 



The necessity for mineral alimentation was affirmed as a general 

 principle as early as L861 by Liebig in his Letters on Chemistry. It 

 is true that Chossaf and Boussingault had called attention to the neces- 

 sity for lime and that Becquerel and liodier had spoken of the need 

 for iron; but these were only special studies. Liebig stated the gen- 

 eral principle: animals require for their proper maintenance albumen- 

 oids, fats, either starches or sugars, and mineral aliments; but it was 

 not Liebig who demonstrated this, it was Forster. 



In fact, the experiment of Forster relates to the entire sum of min- 

 eral matters, not specially to the chloride of sodium. It is an example 

 of complete mini nil inanition, not of saline inanition. It furnishes, 

 however, some information as to the consequences which may follow 

 from the suppression of salt in alimentation. As soon as the regimen 

 was established, the animal showed a considerable diminution in the 

 quantity of salt rejected by the emunctories, though the urea and the 

 organic waste products maintained their usual proportion. The organ- 

 ism, then, retained its mineral matters; the mutations of chloride of 

 sodium engaged in organic combinations were slight. After twenty- 

 six days of this method of alimentation the animal had lost but 7 

 grammes of this chloride of sodium in combination. Its health, how- 

 ever, was much impaired. It grew more feeble day by day. Nervous 

 troubles appeared, consisting at first of habitual inertia, paralysis of 

 the limbs, and later of convulsive seizures and attacks of madness. 

 The gastric secretion diminished at once. Toward the last it no longer 

 contained hydrochloric acid. Grave digestive disturbances finally 

 intervened. The animal, however, lost but little in flesh; its pining 

 away, its corporeal and physical failure, was but the result of the 



"There remained but eight-tenths per cent of the dry weight. 



