218 PRACTICE OF PHYSIC 



tinual waste by the excretions, but are commonly replaced by 

 the aliments taken in ; and if the quantity of aliments in any 

 measure exceeds that of the excretions, an increase of the 

 quantity of the fluids of the body, or, in other words, a plethoric 

 state, must necessarily arise. This, to a certain degree, is re- 

 quisite for the growth of the body ; but, even then, if the pro- 

 portion of the aliments to the excretions, be greater than is 

 suited to the growth of the body, and more certainly still, if, 

 after the growth is completed, when an equality between the 

 ingesta and the excreta should be established, the disproportion 

 still continue, a preternaturally plethoric state must arise. In 

 both cases, it is evident, that the plethora must be prevented 

 or corrected by adjusting the ingesta and excreta to each other ; 

 which generally may be done, either by diminishing the ingesta, 

 or by increasing the excreta. The former may be effected by 

 the management of diet, the latter by the management of 

 exercise. 



DCCLXXXIV. The ingesta may be diminished, either by 

 giving aliment in less quantity than usual, or by giving aliments 

 of a less nutritious quality ; that is, aliments of a substance, 

 which, under the same bulk and weight, contain less of a matter 

 capable of being converted into animal fluids, and more of a 

 matter ready to pass off by the excretions, and consequently 

 less of a matter to be retained and accumulated in the vessels. 



The choice of aliments suited to these purposes, must be left 

 4o be directed by the doctrines of the Materia Medica. 



DCCLXXXV. The increasing of the excreta, and thereby 

 -diminishing the plethoric state of the system, is to be obtained 

 by increasing the exercise of the body ; and generally for ad- 

 justing the balance between the ingesta and excreta, and there- 

 by obviating the plethoric state, it is necessary that exercise, in 

 a due measure, be very constantly employed. 



DCCLXXXVI. The observing abstinence, and the em- 

 ployment of exercise, for obviating or removing the plethoric 

 state of the body, were formerly considered pretty fully, when 

 treating of the gout (DXLVIII. to DLII.), so that the less is 

 necessary to be said here ; and it is now only requisite to ob- 

 serve, that the same doubts, as in cases of the gout, do not 

 occur here with regard to the safety of those measures, which, 



