Scientific Intelligence. 169 
‘Gold prepared in the same way becomes incandescent only at about 
the temp. of 50° cent. 
Paper impregnated in the same manner with the nitrate of silver 
becomes red between 120° and 130° cent. 
A current of per carburetted hydrogen, (olefiant gas,) renders pla- 
tina incandescent at 100° cent. and the gas inflames from time to time. 
Sulphuretted hydrogen produces the same effect at a temperature 
somewhat higher. The sulphur which is deposited on the metal, must 
be cleared by the action of nitric acid, prior to a second experi- 
ment. 
The protoxide of carbon determines the incandescence of platina 
at about 80° cent. 
The force of the combustion produced by a current of hydrogen 
directed on platina is very great, since it requires the presence of only 
an extremely small portion of oxygen. When the current is thrown 
upon the metal in a vacuum, it produces no effect, which proves that 
the effect is not due, as Dobereiner supposed, to the immediate action 
of the hydrogen on the platina. But in letting into the receiver suf- 
ficient air to support an inch and a half of mercury, the platina be- 
came sensibly red, and a thermometer, which, in the vacuum shewed 
no elevation of temperature, was broken by the heat, being incapable 
of rising higher than 150°. The quantity of oxygen in this case 
Was not more than the 18th part of that which the receiver would 
have contained under the common pressure.—Ann. de Chim. Nov. 
1828, 
5. Preservation of bones, and the employment of gelatine.—J. 
Bornaup, manufacturer of gelatine, at Geneva, has furnished the 
editors of the Bibliotheque with the following information. 
It is well known, that the best means of preserving bones, is te 
pass them through a caustic ley, which removing the grease and odor 
which they acquire, allows of their being kept in heaps even many 
years. Bones may thus be preserved in pits, in the ground or under 
water ; which latter mode is preferable, if they are to be employed 
ina few months. ae 
From late experiments, it appears that one of the most econom- 
ical uses of pals consists in uniting it with bread in the form of 
Soup. If it be well deprived of grease, it makes no alteration in the 
appearance of the bread, and prevents it from moulding so easily. 
he bread thus prepared is exactly like biscuit, if it be left a litde 
Vou. XVIL.—No. 1. 22 
