Intelligence and Miscellaneous Articles. 313 



butecl by M. Lassaigne to some change which had probably occurred 

 in the nature of the long-kept solution. 



Journal de Chimie Medicate. — May, 1838. 



NEW COMPOUND OF SULPHATE OF MAGNESIA AND WATER. 



M. Fritzche states that when a concentrated solution of sul])hate 

 of magnesia is exposed to the temperature of freezing water, there 

 soon form, in the midst of small lamellar crystals of ice, a salt 

 white as enamel and in smaller or larger crystals, according as the 

 quantity of the solution is small or great. "When large masses of this 

 solution are allowed to cool during the winter, the salt often se- 

 parates in crystals of a finger's length, and by gently thawing the 

 liquid, they may be separated, for they undergo no change in water 

 at 32°. 



The enamel- white appearance which these ciystals exhibit, arises 

 from their consisting of a great number of still smaller crystals ; the 

 distinct crystals obtained by this process on the large scale have not 

 the enamel tint, but are limpid and transparent. When subjected 

 to a temperature above 32°, this compound soon begins to decom- 

 pose ; water separates ; the crystals become opake, and common 

 sulphate is obtained with seven atoms of water. The new crystals 

 retain their form, but the interior contains small crystals of the 

 common sulphate. These crystals could not be dried even between 

 folds of blotting paper without losing some water, and become 

 slightly opake at the surface : submitted to analysis the crystals 

 were found to consist very nearly of 



One eq. of sulphate of magnesia 60 = 35" 7 7 



Twelve eqs. of water 108 = 64-23 



168 100- 

 L'Institut, Fev. 1838. 



ON CHLORETHERAL BY M. FELIX d' ARCET. 



When rough chloride of hydrocarbon is distilled in a water bath 

 at 122°, there is readily obtained a liquor which boils at 185° Fahr., 

 and this is pure chloride of hydrocarbon ; the distillation then soon 

 stops, and there remains in the retort a liquid of an oily a])pearance, 

 which does not begin to boil until heated to about 284° Fahr., and 

 its boiling point rises to 324°, and then remains stationary. 



This liquid is about one fourth or one fifth of the original product, 

 according as the washing-bottles of the olefiant gas have been cooled 

 with greater or less care. 



Several experiments yielded the same results, and they were per- 

 fectly identical. 



When freed from all extraneous matter, this substance is an ex- 

 tremely fluid liquid, colourless, limpid, and free from the smell of 

 chloride of hydrocarbon. It has however a peculiar sweetish, aethereal 

 odour, resembling that of sweet oil of wine ; it bums, when a taper 

 is presented to it, with a green flame. 



