" MOLECULAR COALESCENCE/^ ETC. 237 



bear some resemblance to the form in which earthy matter is 

 deposited in the skeletons of soine of the Echinodermata. In 

 the month of A])ril oxalate of calcium, triple phosphate, and 

 phosphate of calcium, were severally deposited in albumen 

 at temperatures of 75° — 85° Fahr. The oxalate was obtained 

 in perfect spheres, having radiant but no concentric mark- 

 ings, and greatly exceeding in size any regular forms hitherto 

 obtained. 



The phosphates were found in irregular, elongated, curved, 

 and branching masses, which Avere neither decidedly crys- 

 talline nor decidedly calculous in their internal constitution, 

 but were composed of subcubical fragments, mostly of small 

 size, but by no means uniform, agglomerated in an irregular 

 way. 



At this point the scope of the investigation widened con- 

 siderably. The light thrown upon the nature of the physical 

 conditions under which earthy matter was deposited in ani- 

 mal bodies was sufficient to indicate the great importance of 

 the colloid bed and of the temperature. At once the differ- 

 ence of texture of bony matter in warm- and cold-blooded 

 animals was remembered, and the curious connection between 

 the temperature of the body of animals and the persistence 

 or abolition of sutures, long ago recognised by comparative 

 anatomists, seemed capable of explanation by the facts and 

 the reasonings here founded on them. Bones of the fish are 

 seen interdigitating in the most complicated way Avithout 

 losing their identity. In the reptile they are gathered up 

 into more compact though still isolated masses, the long per- 

 sistence of lines of suture being very characteristic of the 

 class. In the mammal sutures are compacted for the most 

 part in adolescence ; but in the short-lived bird, with its 

 high temperature, sutures are lost in a few months, and a 

 compaction of bone-tissue hardly seen elscAvhere is obtained. 

 It is fair, I think, to attribute this early and complete com- 

 paction to the activity and extent of the vibrations of mole- 

 cules produced by higher temperature.* The linear forma- 

 tions of crystallization arc here most thoroughly disconcerted. 

 Stated broadly, the three most important or, at least, most 

 abundant constituents of these several forms of bony tissue 

 are on the one side a form of animal matter yielding gelatin, 

 and on the other phosphate and carbonate of lime. In a 

 series of experiments albumen was taken as the animal basis, 

 in which carbonate and phosphate of calcium were first de- 

 posited separately at different temperatures, and afterwards 

 deposited together in the proportions which they would bear 

 to each other in bone. 



