180 ACTDS PRODUCED FROM GINGER. 



carbonate of lime with carbonate of lead conld not have 

 prevented me from obtainins; the acid of ginger, because 

 zuigiberic acid must have either a less, a greater, or an 

 equal affinity with sulphuric acid for lime; if a less, the 

 crystals of zingiberic acid ought to hiive been mixed with 

 the sulphate; if a greater, the zingiberate of lime alone, or 

 mixed with the sulphate, suppo:;iiig more lime to be pre- 

 sent than the zingiberic acid could combine with, should 

 have been formed ; and if an equal, a mixture of zingi- 

 berate and sulphate ought also to have been formed. How- 

 . ever, to remove all doubts, experiment was again tried. 



Farther at- Exp. A. One ounce of Jamaica ginger , coarsely pow- 



tempt to ob- dered was infused in three ounces of nitric acid, S. G. about 

 1"350, at a temperature of between 45° and 55°. In a few 

 hours the liquor assumed an olive green colour, and the 

 ginger was reduced to a pulpy mass* During the infusion 

 of the ginger nitrous gas was constantly disengaged, but 

 not in any considerable quantity. At the expiration of four 

 days six ounces of water were added, and the liquor boiled 

 for about ten hours, water being added occasionally so a» 

 to keep the liquor about the same quantity. After boiling' 

 about five hours, the fumes disengaged ceased to become 

 orange on mixing with the external air, but continued to 

 smell acid, and redden litmus paper the whole time. The 

 liquor was now of a light orange colour, much of the sub- 

 stance of the ginger was dissolved during the process, and 

 the remainder was separated by tiltvation. 



The filtered liquor neither gave cloud nor precipitate 

 with lime or barytic water. 



Crystals ol»- (A) About two ounces of the filtered liquor were exposed 



""^^ * to the heat of a lamp, when, after boiling briskly about 



five minutes, nitrous gas was disengaged, and in a little 

 longer time the liquor became rather turbid ; upon which 

 the lamp was removed, and on cooling the liquor deposited 

 about a drachm of crystals. These crystals were quadrila- 

 teral prisms with unequal sides, but the opposite sides 

 equal ; they were intensely acid, readily soluble in water, 

 the solution aflbrding with lime water a dense white preci- 



•pparently of pitate insoluble in vinegar. Hence I presume these were 



•xalic acid. crystals of oxalic acid. 



(B) About 



