216 NATURE AND LIFE. 



Governed by these ideas, Bernard has studied the 

 various active principles contained in opium, as regards 

 their comparative influence over the animal functions, and 

 has ascertained that they exhibit properties not merely 

 differing from, but opposed to, each other. He has made 

 more than two hundred experiments with morphine, nar- 

 ceine, codeine, narcotine, papaverine, and thebaine. These 

 examinations have proved that, among these six principles, 

 only three produce sleep ; these are, morphine, narceine, 

 and codeine. The three others have no soporific effect ; 

 they possess a power, either stimulating or toxic, which 

 rather tends to thwart or to modify the narcotic effect of 

 the former three. In the scale of their power to produce 

 sleep, narceine holds the first grade, morphine the second, 

 and codeine the third. As stimulants, thebaine has more 

 power than narcotine, and the latter more than codeine. 

 And last, as to their toxic quality, Bernard arranges them 

 in the following order, begining with the most poisonous : 

 thebaine, codeine, papaverine, narceine, morphine, narco- 

 tine. We see that the author of these investigations has 

 not been content with merely describing the differences in 

 their action which mark the alkaloids of opium, but that 

 he has also measured the degree of intensity with which 

 each one of them displays the kind of physiological or the- 

 rapeutic activity peculiar to it. 



These studies have been taken up again quite lately, 

 by Rabuteau. This experimenter has examined the ac- 

 tion of the alkaloids of opium on sensibility and on the in- 

 testine, and has made trial of them in a methodical way on 

 the human subject, at the hospitals of la Charite" and la 

 Pitie. The order in which the various principles of opium 

 may be classed, with regard to their activity, is not the 

 same in the case of man as it is with animals. Thus 

 Rabuteau found that morphine, which has relatively but 

 little toxic power over the latter, is in the highest degree 



