2,10 OF THE GROWTH, &c. 



fort tends to open the os tincae, or orifice of the 

 uterus, which has already been gradually en- 

 larged during the laft months of pregnancy. 

 The head of the foetus puflies along againft the 

 margins of this orifice, and dilates it by a con- 

 ftant preiTure, till the moment of delivery, 

 when it opens fo wide as to allow a free pafiTage 

 to the child. 



What renders it probable that the labour- 

 pains are occafioned by the dilatation of the os 

 tincae is, that this dilatation is the only certain 

 mode of diftinguifhing the real from the falfe 

 pains. Women often feci very briflc pains, 

 which are not thofe that immediately precede 

 delivery. To diflinguifli thofe falfe from the 

 true pains, Deventer advifes the accoucheur to 

 feel the orifice of the uterus, and maintains, that, 

 if the pains be true, the dilatation will augment 

 upon the acceffion of every pain ; and that, on 

 the contrary, if the pains be falfe, the orifice 

 will rather contrad: than dilate, or, at Icaft, that 

 it will not continue to dilate. Hence we may 

 conclude, that thefe pains proceed not from a 

 forced dilatation of the orifice of the uterus. 

 The only thing that is embarraffing, is the alter- 

 nation of pain and of eafe experienced by the 

 mother. This circumfi:ance does not perfed:iy 

 correfpond with the caufe we have affigned ; 

 for the gradual and continued dilatation of an 

 orifice fhould produce a conftant pain, without 

 any intervals of eafe. Perhaps the alternations 



may 



