Magendie on Absorption. 291 
much weaker than would have been produced in the usual 
state of the body, by the dose submitted to absorption, and 
were prolonged much beyond the ordinary term. 
Finally, in another experiment, where I had introduced 
as much water (about two litres) as the animal could support 
and remain alive, the effects were altogether imperceptible, 
the absorption was probably prevented. After waiting near 
half an hour for the effects which are generally developed 
in two minutes, I reasoned as follows: if tne distention of 
_ the veins is the cause of the non-absorption, that cause ceas- 
ing to operate, the absorption should take place. I there- 
fore immediately caused the jugular vein of the animal to be 
opened, and I saw with great satisfaction, that the effects 
became manifest in proportion as the veins emptied them- 
selves... « 2 ete 
I then thought of making the contrary experiment; that 
is, to diminish the quantity of blood and to see whether the 
absorption was more rapid; the result proved my conjec- 
tures well founded. About half a pound of blood being ex- 
tracted from an animal, the effects which would not have oc- 
curred until the expiration of two minutes, manifested them- 
selves in Jess than thirty seconds. 
It might nevertheless be suspected that it was less the dis- 
tention of the blood-vessels than the alteration of the blood 
which retarded or prevented the absorption. To overcome 
this objection I made the following experiment; a very co- 
pious bleeding was practised on a dog; the quantity of blood 
was immediately replaced by an equal quantity of water of 
the temperature of 40° (Centigrade) a determinate quantity 
of the solution of nux vomica was introduced into his pleura, 
the effect was as prompt, and as intense as though the na- 
ture of the blood had undergone no change.* It is then to 
® Several attempts were made which, thoug ch thes conldieat auemey 
iv. for whi hii ten m, 1 theles be usefully noted 
here, as they seem to open a new 
