£gg ACTION OF PHOSPHORUS ON ALKALIS. 



Ft epa rat ion of To obtain the mixture of phosphorus with potash, which 



j.nosphorns /or a p. )earec | to us impracticable unless by the method we shall 



nitxuig it with rt ' ... 



alkalis, mention, we fused phosphorus in a phial into which we had 



put some warm water. The phial was shaken till the water 

 was cold ; to accelerate which we immersed it in cold water, 

 after a little while, still continuing to shake it. Thus the 

 phosphorus was reduced to the state of powder. The su- 

 pernatant water being- decanted off, it was replaced by di- 

 luted oximuriatic acid. This acid, we are taught by Mr. 

 Juch of Wurtzburg, has the property of depriving phos- 

 phorus of carbon, if it be true that it contains any. Fiom 

 coloured it becomes white, and in this state the acid is to 

 be separated from it, and the moisture absorbed by blotting 

 paper. 

 Parity of pot- On the other hand we satisfied ourselves of the purity of 

 taiaed bv ba- * ne potash by treating it afresh with alcohol, and, alter fil- 

 iates water. sion, testing it with lime water and barytes water. We 

 \ shall here observe, that lime water is not a certain test for 



determining whether potash retain any carbonic acid ; for, 

 if the mixture be diluted with water, a small quantity of 

 carbonate of lime will be dissolved. This solution does 

 not take place with barytes, and the smallest quantity of 

 carbonate of barytes is always visible, which renders this 

 substance pieferable to lime for examining potash or soda*. 

 Caustic potash was reduced to powder in a giass mortar, 

 and then an equal quantity of phosphorus, prepared as 

 above, was added. To avoid the combustion, which took 

 place before the temperature was lowered, we placed the 

 mortar in a mixture of powdered ice and muriate of soda. 

 A slight trituration was sufficient, and the mixture was im- 

 mediately introduced into a coated stone retort, which was 



Caustic potash * It has long been kmwn, that a concentrated solution of caustic 

 precipitates potash is precipitated by lime water, and that this precipita'e is soluble 

 »iom i me wa- . ^ j g quanUty f wa ter; whence it lias been inferred, that the pot- 

 ter carbonate c l J ' . ' 

 *)i lime that is ain merely took the water from tbejime, and ; he latter fell down in the 

 3o!ublc. caustic stata. But we have found, that this precipitate is in fact a car- 

 bonate of lime, which, thus intimately divided, is soluble in water. 

 We have observed too, that this solution is not owing to an excess of 

 alkali, for, after passing carbonic acid gas into lime water, thepiecipi- 

 tatc separated was equaUj soluble in w;.;lt. yet the liquor was neutral. 



placed 



Mixture of th 

 phosphorus 

 with potash. 



