34 Historical Sketch of Improvements m [July, 



of glim arabic. In this state the nitrate of picrotoxia is acid, 

 and exceedingly bitter. If it be still further dried in a tempera- 

 ture not exceeding 140°, it swells up, becomes opaque, and 

 becomes at last perfectly white and light, like calcined alum. 

 If we keep it in this staite at a temperature below that of boiling 

 water, adding a little water occasionally,, the whole excess of 

 acid exhales, and the taste becomes purely bitter. When thia 

 salt is washed in pure water, the acid is totally removed, and the 

 picrotoxia is separated in the state of fine white plates. 



Muriste of Ficrotoxiti. — Muriatic aeid, of the specific gravity 

 1*145, has little action ou picrotoxia. It dissolves it when 

 assisted by heat, but does not become entirely saturated. Five 

 parts of this acid diluted with three times its weight of water 

 dissolve about one part of picrotoxia at a strong boiling tenapera- 

 ture. The liquor on cooling is converted into a greyi^ crystal- 

 line mass, composed of confused crystals.. When these crystals 

 are well washed, they are almost destitute of taste, and feel 

 elastic under the teeth, Th«y dissolve in about 400 times 

 their weight of boiling water; but ave almost entirely deposited 

 on cooling. The solubility is mush increased by the presence of 

 an excess of acid. 



Phosphate of Picrotoxia. — Phosphoric acid diluted with twice 

 its weight of water dissolves but little picrotoxia while cold ;. but 

 when assisted by heat, it acts pretty much in the same way as^ 

 sulphuric acid, and the hquid crystallizes in the same manner,, 

 ©nly the crystals are smaller. This- phosphate, after being well 

 washed, gives a red colour to vegetable Wues, It dissolves in 

 50 times its weight of boiling water, and the solution become* 

 almost soHd on cooling. The cryatals are needles, retaining aii 

 excess of acid, and having an insupportably bitter taste. 



Carbonate of Picrotoxia. — When carbonic acid is passed 

 through water with which picrotoxia is mixed, a portion of the 

 acid i* absorbed by the picrotoxia ;. for it afterwards dissolves in. 

 acids- with effervescence ; but no solution takes place. 



Acetate of Picrotoxia. — Acetic acid dissolves picrotoxia very 

 well, and may be nearly saturated with it by the assistance of a 

 boiling heat. On coohng, the acetate precipitates in well- 

 defined prismatic needles. This acetate i* soluble m 50 times 

 its weight of boiling water. On coohng, it forma ciystals of 

 o-reat beauty, light, without any aeid smell, and much less bitter 

 than picrotoxia itself. It is decomposed by nitric acid, which 

 disengages the acetie acid. Dilute sulphuric acid has no marked 

 action on it. 



Tartrate of Picrotoxia, — Cold tartaric aeid scarcely arets upon 

 picrotoxia, but it dissolves that substance when assisted by heat, 

 and on coohng, the saltgradua.lly separates in triangular needles- 

 Thi» salt has a very bitter taste. It is soluble in 20 times its weight 

 ofboiling andinlGOtimesits weight of cold water. Thesolutionof 

 itvtliough much diluted with water, is precipitated by lime-water. 



