36 IMPORTANCE OF CHEMICAL SCIENCE 



assuaging his thirst with an apparently refreshing draught ; or 

 when satisfying his hunger, or gratifying his palate, with seem- 

 ingly the most innocent and grateful viands. To the action 

 of Poisons, whether aeriform, liquid, or solid, his life may be- 

 come a sacrifice. How is he to avoid this danger ? or how, 

 when he has incurred it, and is beginning to suffer from its 

 cause, is he to be preserved from the fatal termination of its 

 influence ? The answer is, by the knowledge previously ac- 

 quired of the nature of poisons, and the means of administer- 

 ing antidotes to them, or otherwise counteracting their effects. 

 And this knowledge must be sought by means of many de- 

 partments of Physical Science: chemistry, natural history, 

 anatomy, and medicine must each furnish their contributions, 

 before the nature and mode of action of the poison can be 

 understood ; and these points must be known before any effec- 

 tual antidote or remedy can be applied. Accordingly, such a 

 knowledge of many poisons has been acquired, and so great is 

 its extent, that it constitutes a distinct object of pursuit, among 

 the cultivators of the medical sciences, under the name of 

 Toxicology ; and M. Orfila, in France, and Dr. Christison in 

 our own country, may be named as men of science devoted to 

 this branch of philosophical inquiry. Many volumes have 

 been published on the history of poisons, of which the works of 

 these Professors are the latest, and perhaps the most valuable. 



It is not to be understood from this representation, that I 

 intend to infer that every man should become a Toxicologist. 

 I have merely offered the foregoing statement to prove how 

 important and how necessary is the knowledge of poisons to 

 mankind ; and to enforce the propriety of the acquisition, by 

 every man, of some degree of information with subjects of this 

 kind. How often do we hear of the death of labourers and 

 servants, by suffocation, in consequence of their descending 

 incautiously into old wells and pits long secluded from the 

 atmosphere. A slight knowledge of chemistry would have pre- 

 served their lives, by teaching them, first, that a species of air de- 

 structive of life (carbonic acid gas) is almost always evolved in 

 such situations ; and, secondly, that whenever present, it may 

 be entirely removed by a few pailfuls of a mixture of quick- 

 lime and water, thrown into the pit ; or even still more simply, 

 though not with so much certainty, by the agitation produced 

 by pouring down a quantity of water alone. This science also 

 would have taught them, that the air which is unfit for respi- 

 ration will not allow a candle to burn in it ; and the simple 

 expedient of letting down a lighted candle attached to a cord, 

 would have detected the presence of the noxious gas in the 

 first instance, and ascertained whether it had been entirely 



