INORGANIC SUBSTANCES. 109 



the urine ; and it will be shown hereafter that a temporary augmentation of 

 their amount in that excretion is often traceable to an unusual disintegration 

 of Nervous matter, setting free its excess of phosphorus in the state of phos- 

 phoric acid. Where the largest proportion of phosphorized aliment is taken, 

 there will of course be the largest proportion of phosphatic salts in the urine ; 

 and thus it happens that the urine of carnivorous animals is much more strongly 

 acidified than that of herbivorous, and that the urine of the latter is often alka- 

 line from the abundance of bases and the deficiency of phosphoric acid. 



85. Although Soda has been spoken of as the predominant base of the alka- 

 line carbonates and phosphates, yet the presence of Potash in appreciable quan- 

 tity must not be left out of view, more especially as this substance presents 

 itself in muscle in so much larger a proportion, that its special relation to mus- 

 cular tissue can scarcely be a matter of doubt. The following, according to 

 Prof. Liebig, 1 are the relative amounts of Soda and Potash in the Blood and 

 Muscle of five different animals, the Soda being reckoned at 100. 



Potash in the Blood. Potash in the Flesh. 



Fowl . . '. ". "j""?;. . 40.8 384 



Ox ... :'*' ';""." v'. * 6.9 279 



Horse . . . V' V W ( V < ; ; J 9.5 285 



Fox ... ,^.-,- A .:,,v,- *> 214 



Pike . . . ,**;*wU^ : f i.,V,? i; * ^. ,' 497 



How far these proportions are liable to be influenced by the nature of the food, 

 and within what limits they are normally confined, has not yet been determined ; 

 and it is scarcely yet safe, therefore, to found any theory of disease upon a sup- 

 posed excess or deficiency of the potash base. 3 



86. Although Ammonia is found abundantly in excreted matters, and may 

 be regarded as one of the ordinary products of the decomposition which is con- 

 tinually taking place in the living body, yet it cannot be properly said to be one 

 of its constituents, since it is nowhere found either in the nutritive fluids or in 

 the living solids, so long as they preserve their healthy state. Even in the 

 Urine, when freshly secreted in the state of health, it is positively denied by 

 Prof. Lehmann that Ammonia exists; the precipitate thrown down on the addi- 

 tion of bichloride of platinum (which was regarded by Heintz as indicating its 

 presence) being really a potash salt. When decomposition commences in the 

 fluid, however, a large quantity of ammonia soon shows itself; as it does also 

 in certain states of disease (CHAP. xii. SECT. 3). Ammonia seems to be a nor- 

 mal constituent of the cutaneous and pulmonary exhalations; being found in 

 the sweat, especially that of the axillae, and in the halitus of the breath. 



87. That Iron is a normal constituent of the Human body, has been already 

 pointed out in the account of Haematin (31). It is not by any means con- 

 fined, however, to the red corpuscles; for it exists, though in minute proportion, 

 in the liquor sanguinis in which they float, and it is found also in various solid 

 tissues. The percentage which it forms of the entire ash is, according to Rose's 

 method, in ox-blood 6.84, in milk 10.47, in yolk of egg 1.85, in white of egg 

 2.09, in horseflesh 1.00, in bile 0.23, and in feces 2.09. According to Von 

 Laer, hair contains about 0.4 per cent, of iron, which amounts to no less than 

 from one-ninth to one-half of the entire ash. The presence of this substance in 

 such large and constant amount, especially in the nutritive fluids, shows that it 

 cannot be regarded as an accidental component; but it must be confessed that 



1 "Researches on the Chemistry of Food," p. 107. 



2 The experiments of Dr. Garrod have led him to the conclusion, that the proximate 

 cause of Scurvy lies in the deficiency of potash in the blood ; and that this disease may 

 be successfully treated by the administration of alkaline medicines alone. (See his papers 

 in the " Lancet" and in the "Edinb. Monthly Journal," for 1848.) A much larger induc- 

 tion, however, is requisite for the establishment of this position. 



