Pharmacologia ; ofl 
‘‘ A practitioner being asked by his patient why he put so many 
ingredients into his prescription, is said to have answered more 
facetiously than philosophically, “ iz order that the disease may 
take which it likes best.” A patient in the hands of such a 
doctor reminds our author of the Chinese Mandarin, who, upon 
being taken sick, sends for twelve physicians, and swallows, in 
one mixture, all the potions which each separately prescribes. 
The young practitioner, however, should be reminded that unless 
the mutual actions of bodies upon each other, and upon the 
living system, is thoroughly understood, in proportion as he 
complicates a medicine, he does but multeply the chances of its 
Sailure. 
In describing the errors which may be committed in the com- 
position or directions of a prescription, Dr. Paris suggests 
several useful precautions, and dwells more especially upon the 
necessity of chemical knowledge. “ The file of every apothe- 
cary,” he says, ‘ would furnish a volume of instances where 
the ingredients of the prescription are fighting together in the 
dark, or at least are so adverse to each other as to constitute a 
most incongruous and chaotic mass.” 
“* Obstabat aliis aliud : quia corpore in uno 
Frigida pugnabant calidis, humentia siccis, 
Mollia cum duris, sine pondere habentia pondus.” 
Ovid. Met. lib, i. 19. 
In adjusting the doses of his remedies, experience must be 
the practitioner’s chief, and often only, guide. The tyro is 
apt to suppose that the power of a remedy increases with 
its dose, whereas the dose often determines its specific ac- 
tion. The preparations of antimony vomit, purge, or sweat, 
according to the quantity exhibited; and opium, in large 
and smail doses, generally produces diametrically opposite 
effects. It often may be remarked that large doses produce a 
local, while small doses produce a general, effect; whence it is, 
perhaps, probable that medicinal, like nutritive substances, are 
more readily absorbed into the circulating system, when pre- 
sented in small than in large quantities. A large quantity of 
food, taken seldom, does not fatten so much as smaller quanti- 
ties at shorter intervals, as is shewn in the good condition of 
cooks and their assistants, who are perpetually sipping, but 
seldom feasting: butchers, too, are rarely great eaters, but they 
get fat by the slow but sure process of absorption by the sur- 
face. Our author thinks that it is not pressing the principle of 
analogy too far, to suppose that the action of alteratives, which 
require to be absorbed, may be more effectually answered b 
similar management, that is, by exhibiting small doses at short 
intervals, 
In apportioning the dose of medicines, certain general cir- 
cumstances, which influence their operation, must not be lost 
2B2 
