256 LETTERS TO BROTHER JOHN. 



Again : What is poison ? Is it not any substance 

 which, when taken into the system, has the effect 

 of disordering some one or more of the actions 

 which make up the sum of life ; and which, if taken 

 in sufficient quantity, will destroy life itself? This 

 is the true definition of poison. Is it not, also, the 

 strictly true definition of ardent spirit ? Spirit has 

 the effect of disordering the nervous system to so 

 great a degree, as to produce intoxication ; exciting 

 the brain, sometimes to madness, always to folly, 

 and quickening the pulse in an extraordinary man- 

 ner. Is not this to disorder the functions of life ? 

 And if it be taken in sufficient quantity if a man 

 swallow a pint of over-proof rum at a draught will 

 it not kill him? It will. Wherein, therefore, does 

 spirit differ from poison ? Only in the dose. 



Aye, but (you may say) it is only poisonous 

 when taken in sufficient quantity ! True: neither 

 is prussic acid, neither is arsenic, neither is mercury, 

 neither is opium. All these poisons are daily 

 given by medical men, without destroying life. 

 Why? Because they are not given in sufficient 

 quantity. But will you, therefore, contend that 

 they are not poisons ? 



It is the effect of prussic acid to lower the ner- 

 vous system below the natural standard. It is the 



