24. COMBINATIONS OF OXALIC ACI©. 



Hence it follows, that 100 of potash combine with 97'3 

 of oxalic acid, 



Superoxalate of potash. 

 Superoxakte This salt I obtained frona a solution of the neutral salt, to 

 salt of borrel. which I bad added an excess of ncid. This superoxalate is 

 known rn the shops by the name of salt of sorrel. It is less 

 soluble than the neutral oxalate. >- 



10 gr. urged in the fire yielded 4"91 of fused carbonate 

 of potash n:: 3 •46 of potash. 



10 gr. of the same salt, neutralized by ammonia, and 

 precipitated by muriate of lime, yielded 10*6 of oxalate of 

 lune — 6*58 of oxalic acid. 

 Its compo- This gives for the composition of superoxalate of potash 



* oo'8 oxalic acid, 



34*2 potash. 



100. 

 Consequently 100 of potash combined with 192*4 of oxa- 

 lip acid. 



Dr. Wollaston's quadro-alate of potash. 



Method of This may be obtained in several ways; either by adding 



obtaining • i i i i ■ , ■ , 



qnadroxalate ^cid to the superoxalate; or by causmtj the muriytic, sul- 

 ci" potash, phuric, or nitric acid to act on the superoxalate ; or by boil- 

 ing crystals of oxalic acid in a solution of muriate of potash. 

 What determines the separation of the quadroxalate is its 

 being less soluble than either of the two compounds just 

 examined. 



After having purified the salt, obtained by one of these 

 means, by a second crystallization, I dried it on a water- 

 bath, and subjected it to the same analysis. 



10 gr. urged in the fire yielded 2*7 of subcarbonate of 

 potash— 1*895 of potash. 



10 gr., brought to the neutral state by ammonia, and pre- 

 cipitated by muriate of lime, yielded 1 1*62 gr. of oxalate of 

 lime=7*205 gr. of oxalic acid. 

 part^s!"^^^"*^" 100 gr. of quadroxalate of potash, therefore, are composed 

 of 18*95 of potash, 



72*05 of oxalic acid, 

 9 of water. — ■ 



100. Hence 



