Prof. Muspratt and Mr. J. Danson on Carmufellic Acid. 295 



the deposit from the canary-coloured fluid. • The filtration was ex- 

 tremely tedious ; it occupied upwards of a month : the precipitate 

 was edulcorated completely with boiling water, until the liquid 

 percolating did not redden litmus paper. When cold water was 

 employed, the filtrates were always milky, which, however, disap- 

 peared on boiling. The filtrate was evaporated to a small bulk, 

 when fine yellow micaceous scales deposited. They were col- 

 lected and redissolved in boiling water, then precipitated by ace- 

 tate of lead, and the lead salt washed by decantation to separate 

 the last traces of acetic acid ; an excess of sulphide of hydrogen 

 was next passed through the lead salt suspended in water, the 

 whole boiled and then filtered through pure animal charcoal, 

 which gave a colourless solution that on evaporation yielded to 

 our satisfaction splendent white crystals of the acid. The crystals 

 were insoluble in alcohol, sether and cold water, soluble in hot am- 

 monia, in potassa, and in large quantities of boiling water ; con- 

 centrated sulphuric acid leaves it intact in the cold, but in the heat 

 carbonizes it, giving off sulphurous acid. We have not enume- 

 rated a tithe of the difficulties encountered, as they would only 

 occupy space, and not prove interesting to the reader ; but those 

 wishing to prepare the acid will find the preceding directions 

 sufficiently explicit. 



Behaviour of the Acid with Metallic Oxides. 



On mixing a moderately strong solution of the acid with any 

 soluble salt of baryta, strontia or lime, the whole becomes a 

 perfect transparent jelly of such spissitude as to allow the vessel 

 containing it to be inverted. 



Soluble salts of lead give with the acid a white transparent jelly, 

 copper ... pea-green flakes, 



silver ... white 



oxide of iron ... white 



sesquioxide of iron pale yellow ... 



When the precipitates are dried they occupy a very small 

 space, and much resemble mica in their feel and crispness. All 

 these precipitates are soluble to a certain extent in nitric and 

 hydrochloric acids. The lead salt is perfectly dissolved, the 

 liquid becoming clear, while with the others it remains opake. 



The acid, heated pe7^ se, fuses and gives off fumes resem- 

 bling those from burnt sugar, together with a yellow oil which 

 condenses on the sides of the tubes. 



Analysis of the Acid and its Salts. 



The acid, dried at 100° C, and burned with chromate of lead, 

 gave the following numerical results i^- 33 



