MODE OF MAKING PHOSPHORIC ETIIEtt, ^3 



F, a small copper weight suspended by a string, which 19 

 fiistened by a knot at the hole G in the thickness of the 

 wheel. The string passes through an aperture in the 

 wooden stock and the plate of copper, sufficiently large to 

 occasion no friction. 



li, a loop at the end of the handle, to hang up the instru- 

 ment when not in use. 



To use it the small mortar B is fdled with powder, and the Method of 

 end of the linger passed over its mouth, that no grains may "^"^g*^- 

 remain between the mortar and its obturator. A little priming 

 is to be put into the pan, and the instrument is to be held 

 in a horizontal position in the left hand, while it is hred. A 

 red hot iron skewer is the most convenient for setting fire to 

 the priming. 



The clastic fluids extricated on firiYig the gunpowder im- Its mode of aq. 

 pel the obturator upward, thus turning round the wheel, and ^io"* 

 raising the weighty that resists its action. The strength of 

 tliis action is indicated by the extremity of the pallet E, that 

 marks the degree to which the weight is raised. 



The degree marked good denotes a good powder for shoot- 

 ing; but the farther it goes beyond this, the better the 

 powder. 



The same powder will not always produce an equal ef- A.dapted to the 

 feet on the same instrument; to prove it properly therefore P^n^^^'^^s of the 

 several trials should be made, and the mean of them' taken. oiX^"^^"^ 

 To prove the large grained powder usedfor military purposes 

 other modes must be adopted, this instrument being suited 

 only to the sportsman. 



Mof^e of maldng Phosphoric Ether by means of a peculiar 

 Apparatus; hy Mr. P. F. G. Boullay, Apothecary, at 

 Paris, Read before the First Class of the Institute, March 

 the '23dy I8O7*. 



J30Tri Scheele and Lavoisier had attempted to trans- unsuccessful 

 form alcohol into ether by means of the phosphoric acid, attempts to 



make phos- 

 ♦ Annales de Chimie, vol. Ixii, p. 192, May, 1807. ' phoric ether, 



without 



