Explain the escape of carbon, hydrogen and oxygen.
What becomes of the nitrogenous parts?
How is the soluble ash of the digested food parted with?
The insoluble?
If any portions of the food are not returned in the dung, how are they disposed of?
That portion of the organic part of the hay which has been taken up by the blood of the ox, and which does not contain nitrogen (corresponding to the first class of proximates, as described in [Sect. I]), is emitted through the lungs. It consists, as will be recollected, of carbon, hydrogen and oxygen, and these assume, in respiration, the form of carbonic acid and water.
The organic matter of the digested hay, in the blood, which contains nitrogen (corresponding to the second class of proximates, described in [Sect. I]), goes to the bladder, where it assumes the form of urea—a constituent of urine or liquid manure.
We have now disposed of the imperfectly digested food (dung), and of the organic matter which was taken up by the blood. All that remains to be examined is the inorganic or mineral matter in the blood, which would have become ashes, if the hay had been burned. The soluble part of this inorganic matter passes into the bladder, and forms the inorganic part of urine. The insoluble part passes the bowels, in connection with the dung.
How is their place supplied?
Is food put out of existence when it is fed to animals?