Numb. 417. Beginning 
VOL. XXXVIi. 
PHILOSOPHICAL 
TRANSACTIONS. 
For the Months of January and February , 1731. 
The C O N T E N T S. 
I. A Catalogue of the fifty Plants from Chelfea- 
Garden, prejented to the Royal Society by 
the. Company of Apothecaries, for 'the Year 
1 729 5 purfuant to the Direction of Sir Hans 
Sloane, Bar 1 - Med. (Reg. <Pr<ef. Col. (Reg. Med. 
& Soc. Reg. by IfaacRand, Apothecary } F.R.S. 
II. A Vefcription of the Water- Works at Lon- 
don-Bridge. By H. Beighton, F. R. S. 
III. Epiftola continens Hiftoriam Calculi 
in Vefica f ponte fraEli, &per Urethram feliciter 
excreti ; ad llluftrem Generofiffintumque Virum 
D.Fred. d e Thom, Serenifmo Due 1 
Bru nsvicensi etLunebur- 
GENSI a Conjiliis, Oratorem ejus apud 
Potentiffimum MagN£ Britan- 
N I M R E G E M, nec non (R.S.S. a 'Ll A U- 
RENTIoHeiSTEROjM.P. (prof. Botan. 
in Acad. Julia Helmftadii, <sr<R. S. S. confcripta. 
IV. A Letter from the (Reverend W illiam Der» 
ham, D. D. Canon of Windfor, and F. R S. 
to 
