Intelligence (in4 Miscellaneous Articles. 165 



Heat chloride of lipe till it ceases to destroy vegetable colours. In 

 this case a mixture of chloride of calcium and chlorate of potash is 

 obtained. This is to b? dissolved in hot water, and to the solution, 

 concentrated by evaporation, chloride of potassium is to be added, and 

 then suffered to cool. After pooling, a quantity of crystals of chlorate 

 of potash is obtained, which are to be redissolved and crystallized 

 again to purify them. M- Liebig considers that this will be a cheap 

 process for obtaining chlorate of potash. From 12 ounces of chloride 

 of lime, of so bad quality that it left 65 per cent, of insoluble matter 

 he obtained an ounce of chlorate of potash. 



The only difficulty to overcome in this process is, that the chloride 

 of lime is not so easily decomposed by heat as is generally supposed ; 

 a solution of it may be kept boiling for an hour without losing its 

 bleaching power. The best method is to form a thin paste with chlo- 

 ride of lime and water, and then to evaporate it to dryness : if it be 

 required to prepare it by passing chlorine into cream of lime it is 

 advantageous to keep it very hot. 



The chlorate of potash, which separates from the solution by cry- 

 stallization, has not the form of scales, which it usually possesses, but 

 is prismatic : whether this is occasioned by some admixture has not 

 been ascertained} but on recrystallizing, it is obtained in the usuaj 

 form. 



The solution ought not only to be suffered to cool in order to pro- 

 cure crystals, for the crystallization is far from being terminated even 

 after complete cooling; crystals continue to be deposited for three 

 or four days.— .^nw. de Ch. et.de. Phys, torn. xlix. p. 300. 



COMPOSITION OF CAFFEIN. 



MM. Pfaff and Liebig have given the following as the comDOsition 

 of Cafiein .— *^ 



Four atoms carbon .... 3*0.5750 4979 



Five atoms hydrogen .. 0-31199 508 



Two atoms azote 1'77036 28-83 



One atom oxygen , , . , 1 -00000 1 6-30 



6-13985 10000 



At the request of MM. Pfaff and Liebig, the analysis was also per- 

 formed by M. Wohler; and he obtained 



Carbon 4993 



Hydrogen 5-43 



Azote 28-97 



Oxygen 13-67 



10000 



Ibid. p. 305. 



The following remarks, appended by MM. PfaAand Liebig to the 



results of their analysis, appear to me to constitute a perfect specimen 



of the manufactureof mystery and confusion, which is likclv, if anything 



can do so. to bring the atomic theory into discredit. 



