[ S9§ ] 
cafion before related; not to mention what it muft 
have loft by mere Wear in fourfeore Years. 
We arc told, that they have in the Hofp'.tals of 
Tans human Calculi weighing 3+ Tans Ounces: 
But this in Trinity Library, even at prefent, weighs 
34 Paris Ounces all but 9 Grains ; and mult have 
weigh’d confiderably more when it was whole. Yet 
thefe are perhaps the heavieft that are any-where re- 
corded ; except that very extraordinary one mention’d 
by Dr. Lifter , in his Journey to Paris, p. 232 ; which 
he fays was taken from a Monk A.D. 1690. and 
weighs yi Ounces. 
This Hiftory may confirm to us the Ufefulnefsof 
endeavouring to relieve the Violence of Pain in this 
Diftemper, by altering the Pofition of the Stone in 
the Bladder, either with the Help of the Catheter , 
or by fome proper Alteration in the Pofture of the 
Patient ; fince, with relpeft to the Pain which it 
occafions, the Situation of the Stone appears to be 
of far greater Confequence than its Size. 
XIV. A Letter from the Rev . Charles Lyt- 
telton LL.D. and F. R. S. ‘Dean of 
Exeter to the Prefid ent, co?icerning a non - 
defeript petrified Infed. 
Read Dec. 20 , f I curious Foftil I have now the 
1 5C ‘ Honour to exhibit to the Society, 
is as rare as its Figure is elegant; having been men- 
tion’d by none of our own Writers who treat on 
Foftils, 
