PRODUCTS, ADVENTITIOUS. 



But we have not pushed the use of micro- 

 scopical characters to extremes, persuaded as 

 we are that more has been done to lower than 

 to raise micro! ogy in general estimation by the 

 attempt to make it (in its present- unformed 

 state) the essential and sole groundwork of 

 distinction of organized products. 



Adventitious products present themselves 

 in the solid, the liquid, and the gaseous states ; 

 and this difference of molecular condition co- 

 incides with so many pathological distinctions, 

 that (although some objections may on " tran- 

 scendental " grounds be raised to the pro- 

 cedure,) we shall found upon it a division of 

 the whole into three corresponding groups. A 

 complete description of the Morbid Anatomy 

 of the more complex of the species composing 

 these groups should, we conceive,* comprise 

 that of their material or physico-chemical 



characters ; of their origin, progress, and de- 

 cay ; of their intrinsic morbid changes, (for 

 their lives, as the lives of the organism they 

 inhabit, are liable to variations of health and 

 disease, they are microcosms within a ma- 

 crocosm ;) of the textural alterations they 

 produce in contiguous parts ; and of the 

 modifications their existence entails on the 

 solids and fluids of the economy at large. It 

 is clear, however, that a plan so extensive as 

 this could not be ventured on in the present 

 work ; but, as far as is reasonable, we shall 

 pursue it. 



GROUP I. 

 SOLID ADVENTITIOUS PRODUCTS. 



The group, Solid Adventitious Products, 

 resolves itself naturally into two great classes 



SUB-CLASS I. 



(Saline.) 



Produced by pre- 

 cipitation from 

 secreted fluids. 

 SUB-CLASS II. 

 ( A nimalixed. ) 



Produced by 

 exudation from 



the vessels. 



CLASS I. Non-Plastic Products or PRECIPITATES. 



I- 



Particles. 



II. 

 Masses. 



f A. Calculi. 



*B. 



J. Concretions. 



I. Protein-Compounds. 



(certain forms of the). 



II. Fat. 



III. Sugar. 



CLASS II. Plastic Products or FORMATIONS. 



* Vide Introductory Lecture, Lancet, 1842. 



