120 ANNUAL OF SCIENTIFIC DISCOVERY. 



for storing safely, a farmer would have less hesitation in sowing great 

 breadths of land. He would not be driven to market under an average 

 value, and might choose his own time for selling. The fear of loss being 

 dispelled, people would buy with less hesitation, and the great food stores 

 of the community would, by a wholesome competition, insure the great 

 mass of the community against a short supply. But as long as uncer- 

 tainty shall prevail in fhe storage of grain, so long will it be a perilous 

 trade to those engaged in it, and so long will the food of the community 

 be subject to a very irregular fluctuation of prices. There is nothing 

 difficult in this proposition. It is merely applying existing arrangements 

 to unusual cases. There needs but the practical example to be set by 

 influential people, and the great mass will travel in, the same track. To 

 the wealthy agriculturist it will be but the amplification of the principle 

 of the tin-lined corn-bin, that keeps out the rat from the oats of the stable. 

 * * * Were this mode of preserving grain to become general, the 

 facility of ascertaining stocks and crops after reaping would be very great. 

 The granaries being measures of quantity, no hand-measuring would be 

 needed, and the effects of wet harvest weather might be obviated." 



CAKBONIZATION OF WOOD. 



Extensive experiments under the direction of the French Government 

 have recently been made by Mr. Yiolette on the carbonization of wood. 

 He has found that the carbonization of wood, effected by means of hot 

 steam, commences at 150 deg., centigrade, but that coal gets friable and 

 suited for the manufacture of the finer qualities of gunpowder only when 

 the temperature of the steam reaches 280 deg. At 350 deg. the coal be- 

 comes black, but at 1,000 and 1,500 deg. it gets very black, exceedingly 

 compact, and very slightly inflammable. At the temperature when pla- 

 tina melts, it gets so hard that it is difficult to break it ; it has a metallic 

 sound, and ceases to burn as soon as it is removed from the flame of a 

 candle ; it is then like anthracite. At 280 deg. 40 per cent, of charcoal is 

 obtained ; at the highest degree of temperature it yields only 15 per cent. 

 Slow carbonization produces more charcoal than a rapid one. The coal 

 obtained at 270 deg. contains 70 per cent, carbon, 27 water, and 1.6 hydro- 

 gen. Charcoal produced at 350 deg., and suited for common cannon 

 powder, contains 77 of carbon, 20 of water, and 2 of hydrogen. From 

 that degree up to 1,500 deg. there is no more water found in the coal, and 

 only few traces of hydrogen. When the steam is admitted into the retort 

 containing wood, he was enabled to prodiice at 422 deg. charcoal of the 

 same nature as coal carbonated in the ordinary way at 1,200 deg. The 

 steam assists the decomposition of the wood, and carries off all the volatile 

 substances. In closed retorts wood becomes almost fusible, resembling 

 stone coal, but differing from it only in its composition. In closer 

 retorts, at a temperature of 180 degrees, the same kind of coal may be 

 obtained as in a common way at 280 degrees. The absorption of moist- 



