182 THE SCIENTIFIC MONTHLY
was by no means fortuitous. Including the artificial prodacts the known carbon compoundB exceed 100,000, while there are thonsandB of com- pounda of C, H, and 0, and hundrede of C and H." Carbon is bo domi- nant in living matter that biochemiatry is very largely the ehemiBtry of carbon compounds ; and it is interestiDg to observe that in the evolution of life each of these biological compounds must have arisen suddenly as a saltation or mutation, there being no continuity between one chemical compound and another.
��Fia. 4. (LOWBH) SOIAH PBOUINRNCCB SDBBODHDINa THR SDN. (CPPBB) THB SAMB
oiBiTLT BNUBQBD. Ftom Mt. WIIhdd ObwrTttory.
Phosphoms is essential in the nucleus of the cell,"* being a large constituent of the intranuclear germ plasm, or chromatin, which is the seat of heredity. It enters largely into the structure of nerves and brain, and also, as phosphates of calcium and magnesium, Berves an entirely diverse function as building material for the skeletons of animals.
Sulphur, uniting with nitrogen, oxygen, hydrogen and carbon, is an essential constituent of the proteins of plants and animals." It is espe- cially conspicuous in the epidermal protein known as keratin, which by its insolubility mechanically protects the underlying tissues." Sulphur
■* Henderson, Lawrence J., 1913, p. 193.
M Op. cit., p. 241.
»» Op. eit., p. 243.
- s PirssoD, Lonis V., and Scbuebert, Charles, 1915, p. 434.
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