SCIENTIFIC MISCELLANY. 61 



spirits of turpentine. Large crystals of "hypo" melt down to a liquid 

 after several weeks, and if the bottle be shaken, partially disappear. The 

 turpentine smell nearly disappears. 



"The vapors of iodine, in the course of several months, will penetrate 

 deepl_y into lumps of beeswax. 



"if to a solution of bisulphide x)f carbon there be added twice its bulk 

 of potassic hydrate in sticks, and the bottle be well sealed, the whole will, 

 in two months, become an intense reddish, syrupy liquid, with scarcely any 

 free bisulphide of carbon. 



The curious discovery, says the Scientific American, is announced by Prot. 

 P-. B. Wilson, of Baltimore, that minutely pulverized silica is taken up in a 

 free state by plants from the soil, and that such silica is assimilated without 

 chemical or other change. The experiment consisted in fertilizing a field 

 of wheat with the infusorial earth found near Eichmond, Virginia. The 

 earth, it is well known, consists of shells of microscopic marine insects, 

 known as diatoms, which, under strong magnifying power, reveal many 

 beautiful forms that have been resolved, classified and named. After the 

 wheat was grown, Prof. Wilson treated the straw with nitric acid, subjected 

 the remains to microscopic test, and found therein the same kind of shells 

 or diatoms that are present in the Richmond earth, except that the large- 

 sized shells were absent, showing that only silica particles below a certain 

 degree of fineness can ascend the sap pores of the plant. 



The French have introduced a new substitute for gold. It eonsists of 

 100 parts by weight of pure copper, 14 zinc or tin, 6 magnesia, 3.6 sal am- 

 moniac, 1.8 burnt limestone, and 9 cream of tartar. The copper is first 

 melted, then the magnesia, sal-ammoniac, limestone and cream of tartar, in 

 powder, are gradually added separately. The whole is kept stirred for half 

 an hour, the zinc or tin being dropped in piece by piece, the stirring beings 

 kept up till they melt. Last of all the crucible is covered and the mass 

 kept in fusion for thirty.five minutes. The scum being removed, the metal 

 is poured into moulds. The alloy is fine-grained, malleable, and takes a 

 high polish. It does not oxidize. 



Blue Lamp Chimneys. — JSToted oculists, for instance Graft, Arlt and 

 Stellwag-Carion, recommend either blue, bluish gray or smoke colored 

 glasses as a pretection for weak eyes against the unpleasant effect of red, 

 orange and yellow light. On the same principle, the trying reddish-yellow 

 light of candles, lamps and gas, on normal eyes as well as weak ones, can 

 be pleasantly modified by the use of blue chimneys or globes (or at least of 

 shades for the reflection of the light) colored a light ultramarine blue. A 

 remarkably near approach to a light as agreeable as day light is said to be 

 produced by a petroleum lamp with a round wick and a light-blue chimney 

 of twice the usual length, the latter causing so great a draught that the 

 petroleum burns with a nearly pure white flame. 



