1869.] BOTANY AND ZOOLOGY. 245 



ting wings." Mr. Lord subsequently watched several other balls, 

 in all of which the same series of strange evolutions was carried 

 out. — Once a Week. 



CHEMISTRY AND PHYSICS. 



On new Explosive Powders, by M. Designolle. — Many 

 improvements having lately been made in the art of war, and par- 

 ticularly in the adoption of breech- loading arms, the want has been 

 felt of new powders to meet the requirements of the present artil- 

 lery. This want has been supplied by M. Designolle, who has 

 invented a new system of powders of which carbazotate or picrate 

 of potash is the base. These powders are of four kinds, viz, a 

 musket powder, gunpowder for short bore cannons, slow gunpow- 

 der for cannons with long bores, and an explosive powder for tor- 

 pedoes and projectiles destined for the undermining of fortifica- 

 tions. The principal advantages of these new powders are the 

 following: — Increase of balistic power without increase of explo- 

 sive power ; the base remaining the same, possibility of regulatins; 

 and varying the effects between the limits of one to ten ; also of 

 regulating, at will, the rapidity of combustion of this powder, 

 and of increasing the balistic power without changing the mode of 

 manufacture. Other advantages are — regularity in the manner 

 of action ; suppression of sulphur, and consequently of the vapours 

 of sulphide of potassium and sulphuretted hydrogen ; absence of 

 action on metals and almost entire suppression of smoke. Into 

 the explosive powders only two components enter — picrate of po- 

 tash and nitrate of potash ; the musket and gun powders contain 

 carbon in addition to the above-named ingredients. To prepare 

 these powders, the ingredients are beaten from three to six hours 

 with a proportion of water varying from 6 to l-i per cent., accor. 

 ding to the nature of the mixture ; the powder is condensed by 

 means of the hydraulic press, with a pressure of from 30,000 to 

 100,000 kilos., graining of the powder, and pressing and drying 

 it according to the methods employed for the black powder. In 

 order to increase the balistic power, the relative proportion of pi- 

 crate of potash in the mixture must be increased- For musket 

 powder it has been proved that no more than 20 per cent, of pi- 



