298 Organic Substances and Formations. 



AIDS TO MICROSCOPIC INQUIRY.— No. VIII. 



Oeganic Substances and Formations. 



In a former paper of this series, entitled Notes on Organic 

 Chemistry, vol. vi. p. 428, some illustrations were given of 

 the general principles upon which the elements of living bodies 

 are combined, and we shall now consider the nature of some 

 of the principal substances found in organic beings. 



It astonishes a pretty young lady to tell her that, chemi- 

 cally, she consists of a pail of water, a few gases, some charcoal, 

 lime, iron, phosphorus, and a few et ceteras ; bub the statement 

 is, nevertheless, very near the truth. Organized beings are 

 composed of very similar materials whatever may be their 

 zoological rank, and they do not differ so much from vege- 

 tables in mere composition as was formerly supposed. They 

 contain, for the most part, hard structures and soft ones — the 

 former being for supports, frame-work, etc., and the latter 

 constituting the more vital portions. In man, the hardest 

 material is the enamel of his teeth, and among the softest are 

 his nerves and brains. Human bones, and bones in general, 

 are composed of a soft material, which when extracted from 

 them is known as gelatin, and a hard one strengthening the 

 former, consisting almost entirely of phosphate of lime. It is 

 interesting to compare a hard firm bone of one of the higher 

 vertebrates with the soft bones of cartilaginous fishes, sharks, 

 etc., the magnates of the fish world, whose elevated position 

 is demonstrated to the satisfaction of naturalists by their 

 superior power of devouring their brethren, to which end 

 they are elaborately organized. A terrestrial beast of prey 

 with the soft bones of the shark would not be a successful 

 animal, and should any morbid condition turn out a lion as a 

 gristly monster, " Natural Selection" would take no steps for 

 his preservation, but his days would be soon finished in the 

 stomach of a more earthy-boned brute. In the water, things 

 are different, and the lightness of the shark bone more than 

 compensates for its slighter strength, while its pliability is no 

 doubt convenient. 



The combination of phosphorus, a soft highly combustible 

 solid, of oxygen, the gas that gives its life and fire-sustaining 

 qualities to atmospheric air, and of lime the well-known 

 earthy mineral, results in phosphate of lime, to which bones 

 owe their hardness anfl solidity ; and which meets us again as 

 one of the constituents of wheat flour, and many other sub- 

 stances used as food. The animal derives his phosphates from 

 the vegetable, and when the animal has done with them, and 



