2gR Dattgircus fiiltiiinat!i>g Compounds t/* Siktf, 



compound, hns no fuch property, any farther than may be owing to the matter depotitcd 

 from the alkaline fdlution during the cxficcation. 



" The alkaline liquor containing the fulminarmg filver ought to be poured off from the 

 infoluble powder, and expofed in a {hallow veOel to the air. In confequence of tlic ex- 

 luhtion, black fbining cryftals form on the furface only, and foon join to form a pellicle. 

 As this pellicle adheres a little to the fnlcs of the veflcl, or maintains its figure, the liquor 

 may be poured off by a gentle inclination of the veflel. 



" This liquor will yield another pellicle in the fame w.iy ; but the third or fourth pellicle 

 uill be paler than the former, and weaker in the explofion. The firlt pellicles, when fiowly 

 dried, explode by the touch of a feather, or by their being heated to about 96". 



" The quantity of water in the ordinary aqua ammonix pura: renders it lefs aclive in the 

 folution of the oxide, and is an impediment to the fpeedy formation and feparation of the 

 fulminating filver; and an experimenter who has often ufed twenty grains of the oxide to 

 produce fuccelTive pellicles of fulminating filver, which may be feparatcly exploded with 

 fafetv, and who has perceived that the pellicles never explode whilft wet, if they be not 

 heated, would in all probability rcfolve on the following improvement, and expofe hlmfclf 

 to the unforefeen danger of it." 



DISTILLED water was impregnated with as much pure ammoniac as it could eafily re- 

 tain under the ordinary temperature of the air. A quantity of this llrong ammoniacal 

 liquor, equal in bulk to a quarter of an ounce of water, was placed in a fmall bottle, and 

 24 grains of the oxide of filver, ground to fine powder, were added. The bottle, being al- 

 moft filled, was corked, to prevent the formation of that film which ufually appeared in 

 confequence of the exhalation of the ammoniac in other experiments. 



During the folution of the oxide, bubbles of thogafeous kind arofe from it, and tlie folu- 

 tion acquired a blue colour. 



As no film appeared, the bottle was agitated three or four times in the courfe of as many- 

 hours, in order to promote the folution of a fmall quantity of blackened oxide which re- 

 mained at the bottom. 



The experimenter confidering this as an ample provifion for twenty ditFerent charges, to 

 be exploded in different circumftances, in the prefence of the fociet.y, intended to pour off 

 the folution into as many fmall veffels, and to weigh the refiduary black powder, after al- 

 lowing two hours more for the folution. 



On the fixth hour he took his ufual precaution of wearing fpeftacles ; and obferving that 

 a fmall quantity of black powder ftill remained undiffolved, and that no film was yet formed 

 at the furface, he took the bottle by the neck to Ihake it ; knowing that it might explode 

 by the heat of his hand, if he were to grafp it, and that thL explofion in this circumftance 

 might wound him dangeroufly. 



In the inftant of fhaking, it exploded with a report that dunned him. The bottle was 

 blown into fragments fo fmall as to appear like gtafs coarfely powdered. The hand which 

 held it was impreffe<l as by the blow of a great hammer, and loft the fenfe of feeling for 

 feme feconds 5 and about fifty-two fmall grains of glafs were lodged, many of them deeply. 



