THE VEINS OF LIVING ANIMALS. 
211 
a kind of foreign body, the effects of which have not yet been suffi- 
ciently studied. 
We will add, that, in the second of our experiments there existed 
traces of inflammation of the internal membranes of the right cavi- 
ties of the heart; and it then appeared to us very probable, that 
the prolonged presence of the air in these cavities might have had 
somewhat to do with the existence of that inflammation. 
$ IV . — The proper means to prevent the spontaneous introduction 
of air , and to remedy the accidents produced by its introduction. 
The application of a compressive bandage round the chest and 
belly of a dog has not prevented the introduction of air into the 
jugular vein, whether the animal was in a horizontal or vertical 
position. The experiment, however, not having been made in the 
most precise and satisfactory manner, no legitimate conclusion can 
be drawn from it. We have been enabled by strong compression 
of the chest and belly (compression which, in 1811, Nysten, with- 
out sufficient proof, considered as an efficacious means of remedy- 
ing the accidents produced by the introduction of air into the veins), 
to force from the vein a certain quantity of blood mingled with air : 
but we must not conclude that any great advantage will result 
from this. Our experiments on this point have been much too 
limited. 
\ V . — - The application of these experiments to the introduction 
of air into the veins of the human being during 
certain surgical operations. 
We are perfectly aware with what circumspection we ought to 
proceed, when we draw certain conclusions with regard to the hu- 
man being, from that which takes place in the brute. Neverthe- 
less, there are certain inductions of this kind, the legitimacy of 
which the most strict and severe physiology cannot question. 
Then we are authorised, on the faith of the experiments which 
we have recorded, to believe that air may be introduced into large 
veins divided in operations on the human subject, in the neigh- 
bourhood of the superior part of the chest, and the orifice remaining 
unclosed whether by reason of a morbid state of the tissues or 
some physical or mechanical cause. Not only is this possible, but 
it is, unfortunately, too often the case. It was evidently so in the 
six cases that were briefly noticed in the early part of this report. 
As to the quick and almost instantaneous access of death in cer- 
tain operations when the air obtains admission into the veins, we 
must confess that it is difficult to account for it from the simple 
presence of the air, seeing that, in many cases, the air may be in- 
