CHEMICAL SCIENCE. 209 



with a view of attaining this end, have been made repeatedly upon 

 felspar ; but, owing to the peculiar chemical and physical properties of 

 this mineral, the success of these researches has been doubtful. It is 

 proposed by Mr. Wurtz to make use of the green-sand as a source for 

 obtaining potash, which, he thinks, is far superior to felspar in its 

 adaptation to this purpose. The green-sand of New Jersey, according 

 to Prof. H. D. Rogers, contains from 10 to 13 per* cent, of potash ; in 

 two varieties analyzed by Mr. Wurtz he found 6.38 and 4.94 per 

 cent. ; these latter results were obtained, however, from green-sand in- 

 termixed with earth and sand, while the determinations of Prof. Rog- 

 ers were made upon the material freed as much as possible from impu- 

 rities. Besides potash, the green-sand contains nearly 50 per cent, of 

 silica, with smaller quantities of iron, alumina, magnesia, and water. 

 Considering that the green-sand contained the constituents of alum, 

 with the exception of sulphuric acid, an attempt was made to extract 

 alum from it by the addition of sulphuric acid. This was at first un- 

 successful, owing probably to the presence of protoxide of iron and or- 

 ganic matter. A portion of the green-sand was then gently ignited, 

 destroying the organic matter and peroxidizing the iron. The mass 

 when treated with sulphuric acid yielded common alum, together with 

 small quantities of iron alum, and sulphates of iron and alumina. Up- 

 on the addition of chloride of potassium, all the iron was converted into 

 uncrystallizable perchloride, while the sulphate of potash formed by 

 double decomposition combined with free sulphate of alumina to form 

 common alum. In this way alum was formed in such quantities as to 

 promise the most successful results in the practical employment of this 

 process. The chloride of potassium employed in the process described, 

 Mr. Wurtz has found, may be readily obtained by fusing the green- 

 sand with chloride of calcium. The pulverized and ignited marl is 

 mixed with sufficient quantity of chloride of calcium to form upon fu- 

 sion a pasty mass. The decomposition of the green-sand takes place 

 at a low temperature, and is so complete, that in most cases all the 

 potash contained in it may be readily dissolved out in water, as chlo- 

 ride of potassium. Its separation from the excess of chloride of cal- 

 cium is an easy problem, owing to the difference between their solubil- 

 ities. This application of chloride of calcium will also open a market 

 for the large quantities of this substance which are thrown away in 

 some manufactories of soda-ash. Silliman's Journal, Nov. 



ON THE SECRET OF THE EMBALMING PROCESS. 



THE charge of fraud being often alleged against the Egyptian un- 

 dertakers, on account of the wholesale use of bitumen in the process of 

 embalming, by which the body becomes so charred and calcined as 

 readily to break into fragments, Dr. Corrnack of London has recently 

 published some statements, which seem to show that the application 

 of heat to bodies filled with bitumen was the essential part of the mum- 

 mifying process. In the opinion of Dr. C. mummies owe their preser- 

 vation to creosote, formed by the application of great heat to the bitu- 

 men. No experimenter, says he, has ever yet succeeded in preserving 



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