236 PHYTOCHEMY. 



wood is a proof of the existence of this substance, and of its 

 gradual oxydation by the admission of air. A. F. Mornay 

 has observed a phosphorescent plant, of the family of the 

 Contortae, in Brazil, (Philosophical Transactions, 1818.) The 

 nauseous smell which phosphorus gives out, and the existence 

 of the same in the salts of cyanogen, favour the suspicion, that 

 phosphorus is produced by a certain combination of hydro- 

 gen and azote. We can scarcely doubt of the existence of 

 this combination in the base of cyanogen. We find this 

 matter commonly in a slight state of oxydation, as cyanogen, 

 there being scarcely 2 per cent, of oxygen in it, in the Bit- 

 ter Almond, in the Cherry Laurel, in the Black Alder, and 

 in various other narcotic plants, (Gay Lussac in Schweigger's 

 neuem Journal.) Halogen or chlorine has the same disposi- 

 tion to become volatile, and the same tendency to assume the 

 gaseous form. Its strong attraction to oxygen is the cause 

 why we commonly meet with this substance as hydrochlorous 

 acid, and why we find it in the ashes of plants, in combina- 

 tion with alkahes. 



Iodine is very nearly related to this substance : it is com- 

 monly found as an oxyde in the ashes of sea- weed ; it smells 

 like chlorine, and evaporates, when exposed to heat, with a 

 pui^le colour, and a smell of chlorine. It does not affect the 

 colours of plants either as an acid or an alkali : it is most so- 

 luble in alcohol and ether, but it takes from water, as do also 

 chlorine and azote, nearly two parts and a half more of oxy- 

 gen than its own weight. Even the highly poisonous nature 

 of iodine, which has been lately remarked, favours the idea 

 of its being a compound probiibly of hydrogen and azote. 



362. 



There are some other newly discovered matters In plants, 

 which may be arranged more or less with those. At least, 

 there are some bases of acids, which are probably similar 

 combinations of the elementary matters, as tiiose which form 

 the alkalies. Morphium, which is vniited in opium with the 

 mcconic apid, proves its affinity to alkalies by this circum- 

 stance, that it restores to their forincr colour the blue vege- 



