KKVIKW (>K LJTERATUBE, 19 



magnesium, and iron: iodin occurs also, especially in the thyroid tissues. 



In the liquids of the body the main salts are sodium chlorid, sodium 

 carbonate, sodium phosphate, and potassium and calcium chlorid or 

 phosphate. In considering the organic foodstull's. their value as 

 sources of eneriry, as well as their function in constructing tissue, is 

 emphasized. The salts have 4 no importance from the former point of 

 view. Whatever chemical changes they undergo are not attended 

 by the liberation of heat ener<:y none at least of sullicient impor- 

 tance to be couriered. They have, however, most important func- 

 tions as they maintain a normal composition and osmotic pressure 

 in the liquids and tissues of the body, and by virtue of their osmotic, 

 procure pla\ an important part in controlling the How of water to 

 and from the ti- Moreover, these -ah- constitute an essential 



part of the composition of living matter. In some \\ ay they are 

 bound up in the structure of the living molecule and are necessary to 

 its normal reactions or irritability. I'ven the proteins of the body 

 liquids contain definite amounts of ash. and if this ash is remo\c<! 

 their proper <>usly altered, as i- -ho\\ n b\ the fact that- 



native protein- \\hen made practically a>h-free |o-e their properl \ of 

 ion by heat. The globulin- are precipitate<l from their solu- 

 tions \\lien the >alts are removed. Th- I importance of the 

 ealci oairulation of the blood and the curdling ,f milk 

 also the peculiar part played b\ the calcium, 



pot.-i- :iid sodium salts in the rhythmical cont ract ion- of the 



heart mu-cle and the irritability of musc,ular and nervon- tissues. 

 The -pecial importance of the it for the production of hemo- 



globin i- ill knoun. The nutritive impor the salt- in 



diet ha> been ileinon-traled by direct exjieriinent . 



D" fed b\ FoTSter* upon a die! com|>i^ed of a-h-free fats 



and earboli\ drates. and meats which had been extracted with \\ater 

 until the salts had been reduced. The animals were in a dyini: con- 

 dition at the end of twenty-six t o t hirt \ ->ix da \ >. It i> pro!>able that 

 they would have live.l longer if deprived of food entirely, with the 

 ;>tion of ualer. since the metabolism of the abundant diet pro- 

 vided aided in increasing the los> ,,f ^alts from the body. Lunin'' has 

 described experiments which in<licate that some at least of our salts 

 must be provided for us in organic combination- >uch a- ai'e found 

 in plant and animal food-. In hi- experiments he found that mice 

 fared well on a diet of dried row's milk. If fed, however, on a diet 

 containing the oriranic but ash-free constituents of milk, namely, 

 siiLTar. fat. and casein, together with t he ext racted salts of cow's milk, 

 they died in from twenty to thirty day-. 



ii. Ily-h'iM'. L8 i, j)hy,i..l. <'h.-n,.. 1881, .-7:31. 



