INORGANIC SUBSTANCES. 47 



matters. Finally, the urine of the young calf while living on the milk 

 of the mother is clear and acid ; but after the animal has been weaned 

 and feeds upon vegetable matter, its urine becomes alkaline and turbid, 

 like that of the adult animal. 



9. Sodium and Potassium Sulphates, S0 4 Xa 2 and S0 4 K 2 . 



The sulphates are constant ingredients of the body, and are found in 

 several of the animal fluids, including the blood, the lymph, the aqueous 

 humor, milk, saliva, mucus, the perspiration, and the urine. They are 

 usually, however, in small quantity, as compared with other saline mat- 

 ters. In the blood and the lymph they are much less abundant than 

 either the chlorides, phosphates, or carbonates. In the milk and the 

 saliva there is hardly more than a trace of them ; and they have not 

 been found in the bones, the gastric juice, the bile, or the pancreatic 

 juice. They are most abundant in the urine, where they amount to 

 rather more than one-half the quantity of the phosphates, and they are 

 found also, in small proportion, in the feces. 



The sulphates are introduced into the body, to some extent, with the 

 food and drink. They are present, in minute quantity, in muscular 

 flesh and in the yolk of egg. They exist also in certain vegetable pro- 

 ducts, such as the cereal grains, fruits, and tuberous roots, where they 

 are less abundant than the phosphates, though often more so than the 

 chlorides. Spring and river water, used for drink, usually contains sul- 

 phates, including sulphate of lime, varying in amount, according to 

 Payen, from .003 to .06 per thousand parts. In the water of the Croton 

 river, with which the city of Xew York is supplied, they amount, as 

 shown by Prof. Chandler, to a little more than .007 per thousand parts. 



Beside the sulphates introduced with the food and drink, a certain 

 amount of sulphuric acid originates within the body by oxidation, in a 

 mode analogous to that already described for phosphoric acid. The 

 albuminous substances, which form so important a part of the solid food, 

 contain sulphur as one of their constituent elements, and a considerable 

 quantity is accordingly introduced into the system in the form of organic 

 combination. The entire quantity of sulphur, thus forming part of the 

 organic matters of the human body, amounts, according to Payen,* to 

 about 110 grammes; and at least 1 gramme is taken daily with the 

 albuminous ingredients of the food. A portion is expelled with the 

 daily exfoliation of the hair, nails, and epidermis ; but no such sulphur- 

 ous organic compound is discharged by the urine and feces except in 

 insignificant quantity. On the other hand, the sulphates are compar- 

 atively abundant in the excretions. While they are to be found in the 

 blood only in the proportion of 0.28 per thousand, they exist in the 

 urine in the proportion of from 3.00 to 7.00 parts per thousand, and are 

 discharged by this channel to the amount of about 4 grammes per day. 



These facts indicate that a notable quantity of sulphuric acid is formed 



* Substances Alirnentaires. Paris, 1865. p. 68. 



