of Edinburgh, Session 1870 - 71 . 
373 
are true. Even if his methods are correct, the results are not 
actual values, hut possible values, or statements of what may be, 
not of what has been. 
These results are very different from those of Poppel, Tait, and 
myself, and it is one of the objects of this paper to inquire into 
their value. In doing this, I shall not discuss the method, but 
merely examine the results, by the aid of any obstetrical light 
which I can throw upon them. 
Before proceeding to this inquiry, it is to be remarked that 
Haughton arrives by his method at new results which the methods 
of previous observers did not afford the means of reaching. There 
are, as is universally known, two great forces employed in labour— 
the uterine contractions and the involuntary and voluntary bearing 
down. The former of these forces is peculiar to the parturient 
female. The latter, as Haughton truly observes, is not peculiar to 
parturition, but is “ available to expel feces, urine, or a foetus.” 
Haughton’s plan is, to examine the uterus, measure it, and through 
this, arrive at a conclusion as to its power; then to examine the 
muscles which co-operate to produce bearing down, measure them, 
and through this arrive at a conclusion as to their power. The 
addition of the two results will, of course, give the power of labour. 
As I have already said, this is a dangerous and difficult plan to 
follow, and this is because there is room for error at every 
step. 
The conclusions which Poppel and Tait and myself enunciated 
regarding the power of natural parturition stand on a completely 
different and, it appears to me, far more secure footing. There 
can, indeed, be scarcely any important difficulty raised regarding 
them. The strength of the foetal membranes is ascertained by 
experiment. Certain facts are well known regarding the rupture 
of the membranes generally, and regarding their rupture in the 
labours in which the membranes experimented on were produced. 
These two sets of data, when put together, lead by a process of 
reasoning, which it would be tedious here to recapitulate, to con¬ 
clusions regarding the lower limit of the pow r er of natural labour, 
and regarding the power of labour generally, which cannot, so far 
as I see, be cavilled at. It is evident that this method tests only 
the whole or the combined powers of labour. Tt can afford no hint 
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