Dr. Clarke’s Qbfervatioin on the 
0 
In the year 1753, 'Dr. Roederer published a Paper, De pots 
dcre et longhudine Infantum recens natorum , in the Comment 
taries of the Royal Society of Gottingen, of which the cele- 
brated Haller was the principal inftitutor, and long the pre* 
fident. In this Paper he proves, in the' cleared: manner, by 
inconteftible experiments, the abfurdity of the ideas of obde- 
tric writers with regard to the progrefs of the ovum during 
gedation, and the weight of the foetus after birth. He thews* 
although they date the weight of the foetus, come to the full 
time, to be from 12 to 14 or 16 pounds, that it is more 
generally 6 or 7, and very rarely exceeds eight. This de- 
ferves particular notice for two reafons ; fird, becaufe it ferves 
to fliew how little dependence is to be placed on the aflertions of 
authors who copy each other fervilely, without having recourfe 
to experiment even in the mod: obvious cafes ; and, fecondly, 
becaufe this paper has been overlooked by fome of the mod: 
celebrated writers and teachers of midwifry now living. What 
idea are we to form of the Accuracy of one of our lated 
fydematic writers, who (telling us that he has been a prafti- 
tioner of midwifry, in a capital city* for twenty years, and a 
teacher for more than twelve) dates, in one page of his work, 
-that the weight of a foetus at eight months is about feven 
pounds ; and on the oppofite page, that at full time it weighs 
from twelve to fourteen pounds * i 
Of 27 children, carried to the full period of gedation, 
weighed and meafured in length by Roederer, without any 
attention to the difference of fex, I find, that 1 8 were of the 
male and 9 of the female -fex ; and that -the average weight of 
Sec a Treatife of Midwifry (p. 88. and 89.) diverted of technical terras and 
I'ftrvfe theories , by A. Hamilton, M. D. 8° edit. London, 178-1. 
2 the 
