OF THE SOLIDS. 13 



SECT. III. 



OP THE SOLIDS IN GENERAL, AND OF THE MUCOUS 

 WEB IN PARTICULAR. 



17. THE solids* are derived from the fluids. In the 

 first rudiments of the gelatinous embryo, they gradually 

 commence in their respective situations, and differ in- 

 finitely in their degrees f of cohesion, from the soft and 

 almost pulpy medullary matter of the brain, to the 

 vitreous substance of the corona of the teeth. 



18. Besides the gelatinous (11) and glutinous (15) 

 parts of the solids, earth enters more or less into their 

 composition, and is principally lime united with phos- 

 phoric acid. The bones possess this in the greatest 

 abundance, particularly in advanced age, whereas in 

 childhood the gelatinous matter abounds. 



19. With respect to texture, a great part of the 

 solids consist of fibres more or less parallel. This may 

 be observed in the bones, especially of foetuses,^; in the 



* Hier. Dav. Gaubius, Spec. fa-Miens idemn generalem solidarum c. h. par- 

 Hum. Lugd. Bat. 1725. 4to. 



f" Abr. Kaau Boerhaave, on the cohesion of the solids in the animal body, 

 Nov. Comm. Acad, Petropolit. t. iv. p. 343 sq. 



J The parallel and reticulated bony fibres are most striking in the radiated 

 margins of the flat bones, as we find these in young heads much enlarged by 

 hydrocephalus. I have, in my museum, a preparation of this kind, where in 

 the sphenoid angles of the parietal bones, the fibres are an inch or two in length, 

 distinct and delicate. The hardest parts, the bony and vitreous portions of 

 the teeth, exhibit a structure similar to that which in the zeolite, malachite, 

 hematite, &c. all mineralogists call fibrous. 



