280 ON THE FUNDAMENTAL PROPERTY OP THE LEVER. 



gent*. I wish to receive the opinion of the Society on these 

 and other articles, which 1 have sent. 

 1 am, dear Sir, 



Yours very obediently, 

 Calcutta, Oct. 3, I8O9. W. ROXBURGH. 



MY DEAR SIR, 



^ Captain Richardson having been detained thus long, 



andthisbeing the season for the gaub fruit, I have made a 

 few pounds of the extract, which is packed in the same box 

 with the articles mentioned in my former letter. At the 

 bottom of the box there are ten pounds made with cold wa- 

 ter. Immediately above it is another stratum, weighing six 

 pounds and a half, made with hot water from the refuse left 

 after the cold water process. These two parcels, with that I 

 • sent you formerly, will certainly enable the Society to as- 

 certain and let me know what prospect of success this ex- 

 tract holds out to your tanners. I request the Society will 

 order experiments to be made therewith as early as possible, 

 and I anxiously wait for letters from you acquainting me 

 with the result. 



I remain, dear Sir, 

 Yours truly, 

 Calcutta, Nov. 21, I8O9. W. ROXBURGH. 



*^* Samples of the several articles above mentioned will 



for trial. t* delivered for trial to such persons, as will engage to fa- 



• TQur the Society wit.h the result of their experiments thereon. 



VII. 



Demonstration of the Fundamental Property of the Lever, 

 iy David Brevfster, LL.D. F.R.S, Edin.X 



The fund ^^ '^ * singular fact in the history of science, that, after 



meptal pro- all theattemptsof the most eminent modern mathematicians, 



* See farther particulars of this bark in Dr. Roxburgh's Treatise of Ne- 

 rium Indigo, p. 254 of this volume, under the name of Nerium Anlidysen- 

 tericum. 



J Trans, of the Roy. Soc, of Edinb. vol. VI, p. 370, 



to 



