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Chemistry and Physics, 269 



tals of the metaldehyde of Liebig, and a liquid insoluble in water 

 which when purified proves to be a new modification of aldehyde. 

 The density of vapor is the same as that of elaldehyde ; its properties 

 are however different. It is a thin acrid liquid soluble in alcohol and 

 ether, slightly in water, boils at 257° and changes rapidly into a crys- 

 talline acid not yet examined. It is quile curious that with heat a trace 

 of sulphuric acid reconverts this modification into common aldehyde. 

 The same acid thus forms the substance and reconverts it as we use a 

 high or low temperature. 



Action of Sulphur eted Hydrogen. — A large quantity of this gas pas- 

 sed through a mixture of aldehyde and water causes the deposit of a 

 thick oil, with an insupportable garlic odor. To this oil is assigned the 

 formula C 12 H 13 S 7 — or elaldehyde with S instead of 0, and united to 

 HS, although the analysis agrees well with this — the oil does not seem 

 to be a definite compound — its boiling point, 356°, continually rises. It 

 absorbs ammoniacal gas and produces thialdine. 



From this oil, by exposure to the air, or by the action of acids, is form- 

 ed a substance called by the author acetylic mercaptan C 4 H 4 S 2 ,or 

 aldehyde with S 2 instead of 2 . [It is more probably the sulphur spe- 

 cies of elaldehyde and from it thialdine is immediately derived byNH 3 

 replacing S 2 . We have noticed a similar garlic odor on the decompo- 

 sition of thialdine, and it is not improbable that with an excess of sul- 

 phureted hydrogen, both substances may be formed at the same time.] 



G. C. Schjeffer. 



6. On an Organic Compound containing Arsenic ; by Prof. Wohler, 

 (Liebig's Annalen in Chem. Gaz., Feb., 1849-)— Dry distillation of a 

 mixture of butyrate of potash and arsenious acid, produced a liquid, 

 which when purified strongly, resembled alcarsin in odor and other 



properties, but did not ignite spontaneously. The experiment was con- 

 sidered to prove the formation of alcarsin or some analogous compound. 



G. C o. 

 7. On Liquid Protoxyd of Nitrogen ; by M. Dumas, (Comptes Ren- 

 dus, Nov., 1848.)— The apparatus used for liquefying this gas, was the 

 forcing pump of M. Natterer of Vienna, strengthened by a belt of 

 wrought iron, and supplied with a contrivance for cooling the body of 

 l|e pump and even the piston rod, by the circulation of cold water. 

 Thus arranged, the apparatus is capable of condensing, in two hours, 

 200 litres (53 gals.) of the gas, which must be pure and quite dry. 



The condensation of 20 litres produces the pressure of 30 atmospheres, 

 the remainder furnishes the liquid. Two pounds of nitrate of ammo- 

 n, a are sufficient for the experiment. 



The liquid may be retained in the reservoir for one or two days with 

 but trifling injury to the valve. The first portion which is allowed to 

 escape becomes solid, the remainder and larger part is liquid and may 

 be kept in the air half an hour or longer. Protoxyd of nitrogen is thus 

 found as a clear colorless very mobile liquid ; every drop that touches 

 the skin produces a severe burn ; metals dropped into it hiss like red 

 bot iron ; quick-silver is instantly frozen, as are also sulphuric and 

 »«tric acids; ether and alcohol are not frozen by it; water is instantly 

 frozen and produces by sudden evaporation of the liquid, a sort of 

 explosion. 



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