1820.] Physical Science during the Year 1819. 35 



Oxalate of Picrotoxia.— Oxalic acid, next to acetic acid 

 seems to have the property of saturating picrotoxia most com- 

 pletely. Th^ salt crystallizes in triangular plates, having a 

 moderately bitter taste. It dissolves in 10 times its weio-ht of 

 boiling water, and is, therefore, the most soluble of all the salts 

 of picrotoxia examined by Boullay. 



Picrotoxia acts upon "the living body as a virulent poison 

 occasioning convulsions, which speedily put an end to the life of 

 the animal. Ten grains of it given to a middle-sized dog put an 

 end to Its life in this way in 45 minutes. The same dose of 

 acetate of picrotoxia occasioned some diseased symptoms at 

 first, but in three hours the animal recovered its wonted health 

 and vigour. (See Jour, de Pharm. v. 1.) 



5. Von Mons has announced that M. Brandes has found anew 

 alkalme substance in the seeds of the following plants ; 



Datura stramonium, 

 Hyoscyamus niger, 

 Aconitum napellus! 

 Atropa belladonna, 

 Cicuta virosa. 



He proposes to distinguish these five new alkaline bodies by 

 names derived from the generic appellation of each plant. 

 Hence we must call them respectively, datura, hi/oscyama, aco- 

 mta, atropa, cicuta. Nothing has hitherto transpired respecting 

 the properties of these substances ; but that the plants said to 

 yield them actually do contain some poisonous substances, 

 probably of an alkaline nature, there seems no reason to doubt! 

 (See Jour, de Pharm. vi. 47.) 



IX. Salts. 



1. Solubility of the Salts in Water.— A valuable paper on this 

 subject has been published by M. Gay-Lussac, a translation of 

 which has been inserted in the Annals of Philosophi/, xv. 1. 

 He has given us his method of determining how much of any salt 

 water is capable of taking up. It consists in agitating the water 

 with a greater quantity of the salt than it will dissolve at a given 

 temperature till it ceases to take up any more. The liqind is 

 now poured off, and a given weight of it is put into a balanced 

 Florence flask. This flask" is placed inclined on a sand-bath, and 

 allowed to remain till the whole water is driven off. We have 

 only now to weigh the flask again. The increase of weight 

 obviously denotes the weight of salt contained in the weight of 

 liquid subjected to evaporation. 



M. Gay-Lussac endeavours to show that the quantity of any 

 salt which water will dissolve at a given temperature, if allowed 

 to act upon it for a sufficient length of time, is precisely the same 

 as the water will retain in solution at that temperature, if it has 

 been previously saturated at a boiling heat. I have no doubt 



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