WHAT CONSTITUTES UNWHOLESOMENESS JN MEAT? 281 
ference to the quality of food presented to them, each species 
partaking of strychnine, morphine, or cheese, with equal 
avidity. 
A concise answer to the question, What is a poison? really 
seems more difficult than ever. Men gradually habituate 
themselves to the use of opium, tobacco, &c., till their daily 
dose is sufficient to kill from two to ten of their own species. 
Sheep have been known to consume unwholesome plants till 
their flesh has become uneatable. Goats will feed on hem¬ 
lock, hedgehogs swallow almost anything, and the common 
toad cares little for hydrocyanic acid. Ultimately we come 
to the acari, which appear to enjoy a perfect immunity from 
the usual effects of a so-called poison; for here strychnine is 
only a poison in the same sense that starch would be poison 
to man, namely, in that it does not contain every element 
necessary for the reproduction of tissue. These facts seem, 
Mr. Attfield thinks, to form a chain of evidence more or less 
wanting in certain links, but which appears to indicate that 
a so-called poison is only a poison when the animal taking it 
is unaccustomed to it, or when the amount swallowed is far 
larger than that usually taken into the system. 
Pliny sa} 7 s that Mithridates the Great was the object of so 
many conspiracies during his minority, that by means known 
only to himself he rendered his system poison-proof. This 
is treated as a fable, but in the theory of Mr. Attfield the 
nearest approach to that condition might have been effected 
by continuously taking gradually increased doses of poisons. 
WHAT CONSTITUTES UNWHOLESOMENESS IN MEAT? 
It is rather an important thing to know at what time after 
any given disease from which an animal has recovered flesh 
may be pronounced fit for food. We all know how commonly 
the human subject is affected with pleuro-pneumonia, and 
how frequently pleuritic adhesions are found after death. 
Are old adhesions any sign of unsoundness? or, are they not 
compatible with an entirely healthy composition of fresh 
blood? We know, as matter of fact, that the flesh of 
animals affected with pleuro-pneumonia is sent to market in 
th ree stages : first, so soon as the animal is seized with the 
ill ness. Many a shrewd farmer sends his beast to his butcher 
on the very first signs of disease, before important local 
changes have occurred, and before general emaciation. In 
this stage we are not aware that any proof has been offered 
