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POFULAR SCIENCE REVIEW. 
lie states that the chloral has not been in the same state in all the cases. 
As it is difficult to obtain it pure, it is often a mixed substance. M. Bou- 
chut provides against this by preparing his own chloral from absolute alcohol, 
and not from the hydrated alcohol usually employed in its preparation. By 
this means he always obtains the same results ; and he regards chloral as a 
powerful sedative of the nervous system, and as a narcotic likely to replace 
opium. 
The Medical Men of Moliere's days . — Moliere satirised our profession so 
severely that a sketch of the physicians from whom he drew his conclusion 
is of interest. It is to be found in the New York Medical Journal for 
December. 
The Physiological Action of Pyrogallic Acid. — M. Personne, in his late re- 
searches on phosphorus, was led to conclude that the poisonous properties of 
this substance are due to its absorbing the oxygen of the blood. He was 
from this led to suspect that other powerful absorbers of oxygen, such as 
pyrogallic acid, would produce effects on the system like those of phosphorus. 
His experiments — introduction of pyrogallic acid into the veins — seemed to 
him to prove this view conclusively. The same symptoms as those of phos- 
phorus-poisoning presented themselves. The brown colour of oxidised 
pyrogallic acid was present in the tissues ; and there was the usual fatty 
degeneration of the liver. — Vide Comptes rendus , Oct. 4. 
The Physiological Action of Chloral . — Some curious experiments have been 
recorded by MM. Dieulafoy and Krishaber, which, as it were, reconcile the 
opinions of M. Liebreich, who says that chloral is an anaesthetic, and M. 
Demarquay, who alleges that it is a hyperaesthetic. These experiments seem 
to show that chloral — no matter what the dose — when first administered 
produces a period of excitation, and, if the dose is small, its action stops here. 
If the dose is sufficiently large, the excitation is followed by a condition of 
anaesthesia. Very large doses cause death, which is preceded by a marked 
lowering of temperature. — Ibid. 
Effects of Temperature on Incubation . — In the Comptes rendus of Nov. 15, 
M. Duclos records an interesting fact in the rearing of silkworms. If the 
eggs are previously submitted to a very low temperature they hatch much 
more rapidly than when they have not been thus cooled down. Compara- 
tive experiments, so says the author, have established this fact most conclu- 
sively. The embryo of the silkworm appears therefore to need to be cooled 
down in order to develop advantageously, a fact which would justify the 
procedure practised, it is said, in China and Japan, where cold is employed 
in the rearing of silkworms. 
How Bruit is produced . — At a late meeting of the Amsterdam Academy, 
M. Heynsius gave an account of researches upon the origin of certain bruits 
in the vascular system. In addition to the remarkable facts established by 
him in 1854, he has shown now : — (1) That a bruit may be produced by an 
increased velocity of current, even when there is no enlargement of the 
vessel, and in tubes, either of caoutchouc or in rigid tubes ; and also (2) that 
it matters not whether the dilatation is below or above the contraction. 
