VEGETO-ALKAL1ES. 9J3 



This salt is decomposed by the continued application of chlorine, 

 generally with a change of colour in the liquid to yellow or red, 

 and the formation of a precipitate. The precipitate from the 

 salts of strychnine has been found to contain both chlorine and 

 nitrogen. Quinine and cinchonine salts become with chlorine 

 yellow, rose-red, and then violet-red, while a red resinous matter 

 precipitates, which in the air becomes brown, hard, and pul- 

 verisable. But the nature of the changes which chlorine pro- 

 duces upon these bases remains still to be investigated. The 

 action of iodine is more definite. According to Pelletier, 2 

 parts of strychnine and 1 part of iodine dissolved in boiling 

 alcohol, give a precipitate on cooling, of yellow crystalline 

 spangles, resembling mosaic gold, and hydriodate of strychnine 

 crystallizes out from the liquor when concentrated by evapora- 

 tion. The precipitate appears to contain lj equivalent of iodine. 

 The precipitate produced in brucine, treated with tincture of 

 iodine in the same way is yellow ; quinine and cinchonine give 

 saffron plates by evaporation of the liquid. The vegetable 

 alkalies are recovered unaltered from these precipitates, when 

 they are treated with a dilute acid, iodine being then liberated 

 or by the action of a solution of caustic potash or soda, and 

 then iodide of potassium or sodium is produced at the same 

 time. The substance thrown down by the action of iodine upon 

 morphine is of a brown colour and differs in nature from the other 

 products as morphine can in no way be revived from it. The 

 hydrogen of the hydriodic acid formed with the other alkalies 

 appears to come from the water, but to be derived in the last 

 case from the decomposition of the vegetable base itself. 



Little is known of the action of acids upon the vegetable 

 bases, with the exception of some observations of change of 

 colour which have been made. Thus brucine with a slight 

 excess of nitric acid becomes blood-red, while the colour of 

 pure strychnine is not changed by the same treatment, so that 

 the presence of brucine in strychnine can in this way be de- 

 tected. Nitric and iodic acids colour morphine, and its salts 

 rose-red. Other bases, such as urea and melamine are decom- 

 posed by the stronger acids ; urea being converted by the 

 action of concentrated sulphuric acid into carbonic acid and am- 

 monia, by the assumption of two atoms of water; and mela- 

 mine into cyanuric acid and ammonia, by the assumption of 

 three atoms of water. Thebaine also, exposed to dry hydrochloric 



