, PHYSIOLOGY. 13 



life or external force ; by which means especially, it is changed 

 in the progress of life. 2. The cellular texture may be increas- 

 ed in bulk, and rendered firmer by a new growth taking place 

 in it, as frequently happens in membranes which are slowly and 

 gradually stretched out. 3. The same texture may become 

 weaker by some part of it being eroded by acrid matters gene- 

 rated in the body, or externally applied. 4. It is analogous to 

 this, that when any part is sustained by several layers of cellu- 

 lar texture or membranes, such support is weakened by one or 

 more of these layers being cut through ; and the same weak- 

 ness is induced when any external compression, which, for some 

 time, had been applied, is taken away. 5. The state of the 

 cellular texture is varied by the matter contained in its cells, 

 which is sometimes a matter concreting into a solid mass, and 

 sometimes a preternatural quantity of an aqueous inelastic fluid. 

 The bones formed in the first manner, may again become soft 

 by the hardened matters being dissolved and reabsorbed. 6. 

 When the mobility of parts on one another depends upon the 

 extent of cellular texture connecting them, that mobility is di- 

 minished or destroyed by a great part of the cellular texture 

 being eroded or cut away, and the remaining parts being united 

 together ; so that the parts are now connected by a shorter por- 

 tion of cellular texture than before. 7- Parts naturally sepa- 

 rate may lose their mobility by being joined together by a 

 cellular texture formed between them, as happens when any two 

 surfaces are for some time kept closely applied to each other. 



XXIV. In so far as a solid part is formed by a texture of 

 vessels, its properties (VIII.) may be varied by the different 

 states of these vessels; which, 1. may be more or less full of 

 fluids. 2. They may be changed into a solid mass, by the 

 fluid, contained and stagnating in them, concreting into a solid. 

 3. They may be changed into a solid, if the fluids that should 

 pass through them are intercepted, and the cavity is filled with 

 a cellular texture ; or, 4. They may be changed into a solid, if, 

 by collapse or pressure, the sides of the vessels are applied to 

 each other and concrete together. 



XXV. The Pathology of the simple solids cannot be pro- 

 perly separated from their Physiology ; and, therefore, many 

 different states of these solids, though such as are always mor- 



