510 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



Sulphuretted Hydrogen. 



This compound {(/elas), when used for experimental purposes, is 

 usuall}' olitained from the sulphuret of iron (Ferramas). The 

 Scientific Review, Enghind, proposes the use of sulphuret of cal- 

 cium {calcamas) for this purpose ; the gas is made more easily, and 

 is in a greater state of purity. Calcamas is readily formed l)y 

 mixing, in water, uncalcined powdered gypsum, with one-fourth 

 its weight of powdered gypsum and powdered pit coal, equal to 

 one-third the weight of the whole g3'psum used. The dough is 

 formed into pieces about four inches long by two in breadth and in 

 thickness, which are sprinkled with powdered coal and subjected 

 to a high heat for two hours. When cold, the ofjtside will be 

 found to be oxysulphuret of calcium or calcamast^ but the inside 

 wdll be pure peach-colored calcamas. They should be broken in 

 pieces about nut size and preserved in tight glass bottles. If 

 water is added to these and sulphuric acid [elasot), in small quan- 

 tities, sulphuretted hydrogen {elas) is uniformly generated. 



Impure Wax. 



Mr. Lies Bodart stated before the French Academy of Sciences 

 that a large quantity of wax was imported from America, and is 

 more or less adulterated with paraffine. He proposed a process 

 for separating the paratfine which depends on the etheritication of 

 the wax constituents by means of amylic alcohol (iichelat) and 

 strong sulphuric acid [elasot)] afterwards this compound is con- 

 verted into sulphamylic acid, which wdll not hold paraffine in solu- 

 tion. 



New Blue Color. 



The Moniteur Scientijique contains an account of a new blue 

 obtained by Horace Kcechlin, An alkaline solution of chloro- 

 napthalate of soda [sodam-eurladot) is boiled with zinc in impal- 

 pable powder which, after twenty minute's, results in a pale yellow 

 solution. The liquor is decanted and ammonia {gilan) added, 

 which, in a few hours, changes to a beautiful green. This solution 

 neutralized by an acid, causes the precipitation of brown floccali, 

 which, Avhen collected and dried, appears green, with a metallic 

 luster. It dissolves in alcohol {echelat) with a violet color; this 

 diluted with water, gives a beautiful blue color. It dyes silk 

 blue, aud wool aud cotton when mordanted with albumen. 



