362 Dr. Clarke’s Obfervatlons , &c. 
gered in thofe cafes where the bulk of the male’s head pre- 
cludes the poffibility of his being brought into the world alive, 
either by the efforts of nature or art. The conception of twins 
we have obferved to be more fatal to the mother than that of 
fingle children. The average weight of 12 twins, which have 
occurred to me of late, I find to be 1 1 lbs. a pair. The largeft 
pair weighed 13 lbs. and the leaft 8f. From fome rude at- 
tempts made to afcertain the weight of the contents of the 
gravid uterus in cafes of twin and fingle children, I am in- 
clined to think, that they are to each other as about 15 to 10, 
or perhaps 14! to 9 J. 
Believe me, Sir, with great refpeft, &c. 
J. CLARKE. 
An Abftrad 
