758 
FATAL DOSE OF CHLORAL HYDRATE. 
which the blood is very much depraved, and the various 
fungi to which Hallier and others attribute a pathogenic 
influence. By the general derangement of nutrition and 
the suspension of the concurrent exercise of function in the 
minute elements of the tissues, the natural barriers are re¬ 
moved and these extraneous and more or less hurtful ele¬ 
ments find an easy entrance into the system. 
In connection with this it may be interesting to note that 
in ruminants slaughtered in the most perfect health the 
epithelium of the rumen, and above all of the omasum, is 
frequently found to be but loosely adherent or even partially 
detached. There is some reason to believe that desqua¬ 
mation takes place from these organs at intervals, and with¬ 
out any perceptible interference with the general health; yet 
may not such a partial exposure of the dermis greatly facili¬ 
tate the introduction of such solid bodies ? 
FATAL DOSE OF CHLORAL HYDRATE. 
Dr.B. W. Richardson, F.R.S., has had reprinted from the 
British Association Reports for 1871 his own special report on 
the physiological action of organic chemical compounds. This 
is a most valuable and, we need not say, most interesting 
paper. It deals with several substances, and first of all 
comes chloral hydrate. He has endeavoured to ascertain 
what is a dangerous and what a fatal dose of chloral hydrate. 
The conclusion at which he has been able first to arrive on 
this point is, that the maximum quantity of the hydrate that 
can be borne at one dose bears some proportion to the weight 
of the animal subjected to its influence. The rule, how r ever, 
does not extend equally to animals of any and every class. 
The proportion is practically the same in the same classes, 
but there is no actual universality of rule. A mouse weigh¬ 
ing from three quarters of an ounce to an ounce will be put 
to sleep by one quarter of a grain of the hydrate, and will 
be killed by a grain. A pigeon weighing twelve ounces will 
be put to sleep by two grains of the hydrate, and will be 
killed by five grains. A guinea-pig weighing sixteen ounces 
will be put by two grains into deep sleep, and by five grains 
into fatal sleep. A rabbit weighing eighty-eight ounces will 
be thrown by thirty grains into deep sleep, and by sixty 
grains into fatal sleep. The human subject, weighing from 
]20 to 140 pounds, will be made by ninety grains to pass 
into deep sleep, and by 140 grains into a sleep that will be 
dangerous; finally, he concludes that a dose of 180 grains 
is a fatal dos e.—Journal of Chemical Society. 
