86 THE POISONOUS 



system in any other mode. That objection seems more 

 specious than sound, when we remember that very small 

 doses of poisons are highly effective when inhaled by the 

 organs of respiration. Thus a very few drops of chloro- 

 form will, by inhalation, produce effects on the nervous 

 and vascular systems, more potent than can be created 

 by any dose, however great, thrown into the stomach. A 

 drachm of ether inhaled from a bag, will intoxicate, stu- 

 pefy, and prodigiously excite him whom ten or even 

 twenty times that quantity would not greatly move by 

 the stomach. So, while it requires not less than thirty 

 grains of arsenic (Christison) to kill an adult, I have known 

 nearly fatal results from the inhalation of less than half a 

 grain of arseniuretted hydrogen. Now it is obvious that, 

 of the small quantity of the respired articles mentioned, a 

 much smaller quantity is absorbed by the pulmonary mem- 

 brane, and passes into the circulation. Of the few drops 

 of chloroform used, at least nine-tenths must be exhaled 

 by the breath, and thrown away. But when organized 

 substances find their way into the tide of blood, and that 

 too with vital energies capable of reacting on the elements 

 of the sanguine current, it requires but little acquaintance 

 with physiological and pathological phenomena, to induce 

 us to dread the most fearful results. Even when their 

 vital powers are destroyed by mechanical or chemical pro- 

 cesses, vegetable poisons act, in the smallest portions, with 

 great violence. How much strychnia, or digitalia, or 

 aconita is requisite for the disturbance of functions, or the 

 arrest of vital action ? Certainly much less than we may 

 readily suppose could be inhaled by a sleeper, if such things 

 were suspended in his atmosphere, even with faint diffusion. 

 But the experiment of Prout during the cholera in London, 

 in 1832, if to be relied on ? showed a gain in atmospheric 



