358 
AERIGO VISENTINr. 
for use, but care must be taken to maintain them for half-an- 
liour at 21“^ prior to planting them. Nicolle, Massaglia and 
others have employed aseptic puncture of the heart in order 
to obtain the rabbit’s blood in a sterile manner. Although 
this method, after some experience, succeeds fairly well, it 
never allows so large a quantity of blood to be obtained as 
from the carotid, and I have adopted with constant success 
this procedure, which, moreover, is used also in Mesnil’s service 
at the Pasteur Institute in Paris. The aneethetised rabbit is 
fixed in a manner which exposes the throat; the skin, pre- 
viously disinfected and carefully shaved, is cut with aseptic 
precautions along the median line and the trachea is laid bare, 
taking care not to wound the blood-vessels ; at the side of 
the trachea the carotid is easily found and is isolated from the 
nerves without injuring them, and is tied with sterile silk as 
near as possible to the skull. It is seen that at the level of 
the thyroid gland the thyroid artery arises from the carotid, 
and this is isolated and tied near the carotid and cut above 
the knot in order to have it as a firm stalk for holding and 
raising the carotid with a forceps later on, without diminishing 
its lumen by taking hold of its wall directly. As a greater 
precaution at this point I pour a little alcohol on the artery, 
and then I cut it near the cranial ligature and collect the jet 
of blood in a sterile Erlenmayer flask containing the usual 
glass beads in order to defibrinate the blood. With the 
forceps which holds the carotid by the stalk formed by the 
stump of the thyroid artery, the carotid can be held within 
the orifice of the Erlenmayer flask without touching its walls 
(which, moreover, are previously sterilised in the flame) until 
the blood is drawn. 
By this method as much as 55-60 c.c. of blood can be 
obtained from a rabbit of medium size without the animal 
dying, if care be taken to tie the cut carotid quickly and to 
sew up the wound rapidly without chloroforming the animal 
too much. The operation, when a certain expertness has been 
acquired, may last only a few minutes. 
It is necessary that I should make some remarks with 
