LABOR-PAINS. 277 



after the delivery of the child, which does not change the intermit- 

 tent character of the pains. 



694. In stating that the cause exists in the cessation of the con- 

 traction of the muscular fibre, as insisted on by Millot, who thinks 

 he has made a great discovery, we fall back again to the petitio prin- 

 cipii for which A. Petit has already been censured, above: this is to 

 displace and not to solve the problem. 



695. During the contraction the blood is forced back into the 

 torrent of the general circulation, says Dr Dewees; the womb 

 grows pale, and the contraction ceases; a new affluxion takes place, 

 and the contraction immediately returns. Sic; but this explanation, 

 which in fact is perfectly similar to the one which I have been just 

 now opposing, is liable to the same objections, and not at all more 

 admissible. 



696. In conclusion, we do not know the cause of the intermit- 

 tence of the uterine contractions, any more than we do that of the con- 

 tractions of the heart, the intestines, and the muscles in general, 

 or that of all imaginable intermittence, whether functional or 

 organic. Inasmuch as we cannot grasp a body strongly in the 

 hand without being soon obliged to relax it, wherefore should it be 

 supposed that the contraction of the womb does not require to be 

 alternated with relaxation? The nature of the phenomena is simi- 

 lar in each of the cases; its cause must be identical, and I cannot 

 perceive why we should with so much ardor seek for it in the one, 

 when we have, in some measure, agreed to abandon it in the other. 

 It is a question which will doubtless long remain unsolvable, but 

 which belongs much more to general physiology than to tokology 

 in particular. 



§. V. Of the Dilatation of the Os Uteri. 



697. Pain is the first symptom of labor; but it is neither the 

 most essential nor constant one; for, as has been pointed out by 

 Levret, Denman and Hopkins, it may be conceived, that there may 

 be cases in which it is possible for women to be delivered without 

 any pain, whereas it is materially impossible for her to be so with- 

 out the dilatation of the os uteri. This process of dilatation, which 

 is wholly subordinate to the power of the uterine contractions, re- 

 quires to be well understood. It is slow and not very preceptible 

 at the commencement, but is effected with great rapidity towards the 

 close of labor. It generally requires more time to enlarge it to 

 the size of a crown piece, than to complete its dilatation, when its 

 diameter is about three inches. The orifice, which is for the most 

 part very thin and somewhat sharp, when touched at the beginning, 



