o^ OPIUM, 34:9 



This property, was considered not only as not being derived Effects of 

 from the nervous system, but capable of being encreased. E^sys^em. 

 diminished, or exhausted by the application of external 

 powers, which had no effect upon the nervous system, and 

 that it was, to use the words of Dr. John Brown, as ap- 

 plied to his principle of excitability, " Una toto corpore et 

 indivisa proprietas." 



To ascertain how far some of these opinions were con- 

 sistent with the laws of the animal ceconomy, I instituted a 

 set of experiments, which formed the subject of an inaugural 

 dissertation, published in the year 1790. It appeared to 

 ffie in consequence of that investigrtion, that several of the 

 above-mentioned opinions, viz. That opium did not ^t 

 upon the nervous system; that it acted upon the blood; 

 that its effects conld be extended by means of the one and 

 indivisible property of irritability, had been founded upon 

 reasons which were very unsatisfactory. 



This publication being calculated principally for the 

 meridian of Edinburgh,was confined to that place,, and the 

 question, taking in a general point of view, was left un- 

 determined. 



Since that time I find, from the perusal of a work, called 

 '•^ Medical Extracts" written by a gentleman of some 

 ability, but of more imagination th?iu judgment; that the 

 opinions of Fontana are not only sanctioned by respectable 

 authority, but are considered as generally known, under- 

 stood and acted upon. I have, therefore, thought it ne- 

 cessary to collect into a short point of view the facts, re^ 

 lated by Fontana, and the general conclusions he drew from 

 them, and to compare them with the principal facts, esta- 

 blished by the investigation above alluded to, 



'« I* destined, says Fontana, 300 frogs for these ex- 

 periments, and by means of pincers and scissars, I laid bare 



the expenditure, thus occasioued, was supplied by the influx of a 

 new quantity from the general stock in the system ; thus the con- 

 tinued action of a stimulant power, keeping up a continued ex- 

 penditure, there would be a succession of new influxes until; the 

 whole irritability of the body was consumed by the repeated wants 

 of that part to which the destructive agent was applied. 

 * Medical Extracts 630. Vol. 3. 



the 



