Scientific Intelligence. 101 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry and Physics. 



1. Congelation of Mercury in three seconds, by virtue of the sphe- 

 roidal state, in an incandescent crucible, (Letter from M. Faraday to 

 Boutigny, Ann. de Chim. et de Phys., xix, May, 1847, p. 383.)— In 

 producing congelation of mercury by virtue of the spheroidal state, I 

 first heated a crucible to redness and maintained it at this temperature ; 

 1 then introduced some ether, and then solid carbonic acid ; into this 

 mixture in a spheroidal state, I inserted a metallic capsule containing 

 about 31 grammes of mercury, and in two or three seconds it was 

 solidified. It seemed strange indeed that mercury put into a red hot 

 crucible should come out congealed. 



2. On a new Test for Prussic Acid, and on a simple Method of 

 preparing the Sulphocyanid of Ammonium ; by Prof. Liebig, (Liebig's 

 Annalen, Jan., 1847 ; Chem. Gaz., April, 1847.)— When some sul- 

 phuret of ammonium and caustic ammonia are added to a concen- 

 trated aqueous solution of prussic acid, and the mixture heated with 

 the addition of pure flowers of sulphur, the prussic acid is converted 

 »n a few minutes into sulphocyanid of ammonium. This metamor- 

 phosis depends on the circumstance, that the higher sulphurets of am- 

 monium are instantly deprived by the cyanid of ammonium of the 

 excess of sulphur they contain above the monosulphuret ; for instance, 

 »f a mixture of prussic acid and ammonia be added to the pentasul- 

 phuret of ammonium, the solution of which is of a deep yellow color, 

 and the whole gently heated, the sulphuret of ammonium is soon de- 

 colorized ; and when the clear colorless liquid is evaporated, and the 

 admixture of sulphuret of ammonium expelled, a white saline mass is 

 obtained which dissolves entirely in alcohol. The solution yields, on 

 cooling or evaporation, colorless crystals of pure sulphocyanid of am- 

 monium. Only a small quantity of sulphuret of ammonium is requisite 

 to convert, in the presence of an excess of sulphur, unlimited quantities 

 of cyanid of ammonium into sulphocyanid; because the sulphuret 

 °f ammonium, when reduced to the state of monosulphuret, constantly 

 reacquires its powers of dissolving sulphur and transferring it to the 

 cyanid of ammonium. The following proportions will be ^found to 

 be advantageous :— 2 oz. of solution of caustic ammonia of O-yp spec, 

 grav. are saturated with sulphuretted hydrogen gas ; the hydrosulphuret 

 °f ammonium thus obtained is mixed with 6 oz. of the same solution of 

 ammonia, and to this mixture 2 oz. of flowers of sulphur are added; 

 a «<* then the product resulting from the distillation of 6 oz. prussiate of 

 Po^sh, 3 oz. of the hydrate of sulphuric acid, and 18 oz. water. I his 

 future is digested in the water-bath until the sulphur is seen to be no 

 [onger altered and the liquid has assumed a yellow color ; it is then 

 h <*ted to boiling, and kept at this temperature until the sulphuret of 

 JJjmonium has been expelled and the liquid has agam become colorless 

 The deposited, or excess of, sulphur is now removed by filtration, and 

 ^e liquid evaporated to crystallization. In this way from 3\ to 3$ oz. 



