C 590 ] 
IV* Ohfervatwns and Experiments molth Mad- 
der-root, blotch has the Faculty of tinging 
the Bones of living Animals of a red Colour y 
hy M. Du Hamel du Monceau, F. R. S. &c. 
communicated in a Letter to Sir Hans Sloane, 
Bar^- Br. R. S. Tranjlated from the French 
ly T. S. M 2). F. R. S. 
I N the February iy^7.{N, S.) Monfieur 
Geoffrey communicated to the Royal Academy 
of Sciences at Raris, the following Obfervation, 
extraded from a Letter of Sir Hans Sloane-, Bar^- Pre- 
iident of the Royal Society of London^ to him. 
‘‘ Mr. Belchiert a Surgeon, and Member of that 
Society, dining one Day with a Callicoe-printer, 
remarked that in a Leg of frefh Pork, thePleih of 
“ which was well-tafted, the Bones were red. He 
‘‘ asked the Caufe of fo fingular a thing, and was 
“ told, that thefe Callicoe-printers make ufe of the 
“ Rubia TinBorum^ or Madder-root, to fix the Co- 
“ lours printed on the Cloth. Some of thefe Colours 
are made with Preparations from Iron, others with 
a Mixture of Alum and Sugar of Lead. The Parts 
‘‘ printed with the Preparation of Iron, produce 
Black and Purple ; thofe printed with the Mixture 
*'■ of Alum, Red of different Degrees. Thefe Cal- 
“ licoes are afterwards boiled in a Copper with Bran, 
“ in order to clean them from a dirty red Colour 
occafioned by an Infufion of Madder-root, In 
fine, that this Bran fhould not be loft, though 
“ charged 
