22 
POPULAE SCIENCE EEVIEW. 
Theine is a compoimd formed in tea and coffee, and wliicli 
can be separated *in the form of white crystals. When given 
to frogs it speedily paralyses and shortly after kills them. It 
therefore undoubtedly acts on the nervous system, and it is 
probably this paralysing or sedative action that commends 
theine to the busy, excited populations of Europe. It should, 
however, be remembered that it is a poison, and may be taken 
to excess. I have known many instances of severe dyspepsia 
and a long train of nervous symptoms immediately disappear 
on the suspension of tea and cofiee. 
Alcohol is another substance which addresses the nervous 
system. It first excites and then depresses and overcomes. 
It has been the great tempter and curse of man since the 
days of Noah. It has been hailed by poets and praised by 
prophets, and, again, driven from society as a devouring' 
beast. It may, perhaps, be safely advanced that, with his 
present tendency to abuse this substance, man would be 
better without it. Nevertheless, if guided by reason, it may 
be made by man an alleviation of his sorrows, a protection to 
his health, and a harmless contribution to the pleasures of his 
social meals. The great question is, how much may be taken 
.from day to day with impunity. Without going into any 
question of its action on the system, whether it is partly 
burned or all got rid of by the secretions, I would say that my 
experience is that a healthy man, taking open-air exercise 
every day, cannot safely consume more than two ounces of 
alcohol daily. Roughly, this quantity is represented by a pint of 
strong ale, or a quart of London porter, or four glasses (or eight 
ounces) of port or sherry, or eight glasses (or sixteen ounces) of 
hock or claret. More than this may be excess ; but every man 
should be the judge of his own requirements. When alcohol 
affects the head, or produces thirst, or deranges the stomach, 
or liver, or kidneys, it should be given up or reduced. There 
is no doubt, however, on my mind that men, women, and chil- 
dren can maintain their health through long periods without 
having recourse to alcohol at all. 
Tobacco cannot be regarded as a food at all : at best it is 
but an indulgence. Nevertheless, indulgence is lawful, and 
the question comes as to what injury is inflicted on the system 
by tobacco. Like other narcotics, it obeys the law that, if a 
second dose be not taken till the effect of the first is gone off, 
it can produce no permanent injury on the system. Tobacco- 
smoke has not the power which alcohol possesses of destroying 
the tissues and interfering with the nutrition of the body, and 
consequently, even when taken to excess, does httle harm as 
compared with alcohol. Its allurements for mankind have been 
much more universal than even alcohol. With the exception 
