236 PLYMOUTH INSTITUTION. 



Arsenic, he staled, was very commonly used as a poison. 

 Modern chemistry could now detect the presence of the four 

 hundredth part of a grain. 



He remarked that prussic acid had been made so strong as^'46 

 kill a man when applied to the skin of tlie arm. 



Opium, he stated, was of interest not only as a poison, but also 

 as an article of luxury; and stated that 16,000 pounds were 

 annually consumed in Great Britain. Its effects on the consti- 

 tution, when habitually taken, he said were various, but that in 

 general they were of a most fatal character; and in illustration 

 cited that singular literary production — *' The Confessions of an 

 English Opium Eater:" he strongly recommended the book for 

 perusal, as containing many singular facts relative to the pernicious 

 practice of opium eating. The Opium Eater took at one time 

 the enormous quantity of 320 grains of solid opium per diem. 

 Mr. S. said it was consoling to find that such a habit, contracte<l 

 by years of practice, and bound on its victim by the most 

 powerful links, could at length be relinquished. Mr. Swain 

 quoted several passages from the book in illustration of its style. 



Mr. Swain then adverted to the medicinal exhibition of poisonous 

 bodies. He stated the healing virtues of many of the most 

 deadly of these substances, and showed that we derive many 

 blessings from their proper use. 



In conclusion he remarked that poisons are to be regarded in 

 their relation, not to a species but to a world, and mentioned the 

 fact, that many substances that would poison man are wholesome 

 food to other creatures of the animal creation. 



In the course of the lecture, Mr. S. exhibited the stomach pump, 

 and explained its application by a diagram. 



Marcu 5th. — Mr. W. Wyatt's Lecture on the Teeth of 

 Animals. 



We could not allempt to give an abstract of this paper, with any 

 hope of doing so effectively. It contained such a mass of highly 

 condensed matter, expressed in language so terse, that it was 

 itself a highly finished abstract. The following extracts cannot 

 fail to gratify the reader. 



The formation of the teeth takes place in cavities of the jaw 

 bones called Alveoli, or sockets. In the foetus, and sometimes 

 even as late as at the time of birth, there is instead of these sockets 

 ^il longitudinal and deep groove occupying a considerable length 

 of the jaw. By degrees the bone forms partitions in this groove, 

 until at last the sockets are all distinct cavities, open above, and 

 lined by a continuation of the periosteum from without. The 

 sockets for the permanent teeth are not formed until a later 

 period. Each socket contains a membranous capsule the external 

 surface of which is firm and vascular, and in contact with the 



