88 Dr. Haighton's experimental Inquiry 
the ordinary course of her operations, she suffers an impedi- 
ment which a physiologist may have produced to thwart her 
designs. In the first case, she may be provided with an expe- 
dient ; in the last, she will probably be left without resource. 
Here again we may notice the experiment mentioned by 
Nuck, which, though under similar circumstances, was at- 
tended with a different result. Some who feel themselves 
disposed to venerate his authority, will probably oppose his 
experiment to mine, and think it incumbent on me to account 
satisfactorily for the difference. I can by no means acknow- 
ledge such an obligation ; for to confer validity on experiment 
by reasoning, is to invert the order of inquiry, and support 
facts by conjectures. It is sufficient for my credit to be able 
to adduce evidence of the truth of what I advance, and for 
this evidence I rely on my preparations. 
The train of reasoning which I have lately pursued, led me 
to extend my inquiries into this particular question still fur- 
ther ; and as in the last experiments the vesicles were known 
to be just on the point of bursting before the tube was cut 
through ; the next step in the inquiry appeared to be, to deter- 
mine the consequences of dividing the tube a short time after 
the rudiments of the foetus had passed. Will the procreative 
operations be suspended, if the tube be cut through after the 
ovum is deposited in the uterus ? 
EXPERIMENT. 
I repeated the operation on two rabbits, one of which had 
received the male two days and eighteen hours, the other 
two days and twelve hours. I knew from my own experi- 
ments, as well as those of De Graaf, that the vesicles had 
