C 777 ] 
accident or defign, (let it be from its being mixed 
with iron, or any other caufe whatever) brafs mull: 
be a very improper metal for compafs*boxes, as it 
may occaiion many fad and fatal accidents. 
Norwich, O&ob. 20th, 1758. 
It is well known, that brafs has been fometimes 
found to affedt and diflurb the magnetic needle j but, 
to give magnetifm and polarity to brafs, has not, that 
I have yet heard, been before attempted. I there- 
fore have taken the liberty to lay the above account 
before this Royal Society, and have alfo brought the 
pieces of brafs mentioned therein, which have been 
thus made magnetical. 
London, H. Baker. 
Nov. 15. 1759. 
CVII. An Account of the Sea Polypus, by 
Mr . Henry Baker, F. R. S. 
To the Right Honourable the Earl of Maccles- 
field, Prefident of the Royal Society. 
My Lord, 
Read Nov. 23, TT n0 w return the marine animal your 
J 75 8 - Lordfhip did me the honour to re- 
commend to my examination j which I find to be a 
fpecies of one kind of the Sea Polypi, mentioned by 
naturalifts ; but I think not very accurately deferibed. 
The kinds of Sea Polypi are underftood to be, 
Vol. 50. S G Fir A 
