392 MR C. G. WILLIAMS' RESEARCHES ON 



It is evident that ethyl-chinoline is isomeric with cryptidine, the new base 

 to be described further on. 



Action of Oxide of Silver on Iodide of Ethyl-Chinoline. 



Hydrated Oxide of Ethyl-Chinoline- Ammonium. — A solution of iodide of ethyl- 

 chinoline is decomposed with ease by oxide of silver, even in the cold, a colourless 

 strongly alkaline fluid being formed, containing the fixed base corresponding to 

 the hydrated oxide of tetrethylammonium. The solution instantly reddens tur- 

 meric paper, and restores the colour of reddened litmus. It precipitates solutions 

 of sulphate of copper, sesquichloride of iron, acetate of lead, and corrosive subli- 

 mate. The addition of a small quantity to a red solution of bichromate of potash 

 renders it yellow, by neutralizing the second equivalent of chromic acid. The 

 solution of the base decomposes chloride of ammonium, liberating the ammonia 

 freely. 



The heat of a water-bath decomposes the solution of the hydrated oxide, with 

 production of a splendid crimson colour, the sides of the basin where the liquid 

 has dried becoming a brilliant emerald green, passing in a few seconds to a blue 

 of great beauty and intensity. These colours, like those to be mentioned pre- 

 sently, evidently depend upon oxidation, and would require a very large amount 

 of material to follow out in detail. When the solution of hydriodate of ethyl- 

 chinoline is heated on the water-bath with excess of oxide of silver, a volatile 

 product is evolved, acting strongly upon the eyes. 



Action of Sulphate of Silver upon Hydriodate of Ethyl-Chinoline. 



If hot solutions of sulphate of silver and hydriodate of ethyl-chinoline are 

 mixed, double decomposition ensues, without any further action taking place, the 

 solution of sulphate of ethyl-chinoline remaining colourless, and the iodide of 

 silver separated being of the normal tint ; but, if it be attempted to concentrate 

 the solution by evaporation on the water bath, it undergoes a curious metamor- 

 phosis, the sides of the dish, where the solution has dried, become a deep pure 

 blue, but, as the evaporation proceeds, the solution becomes crimson, and when 

 dry, the mass is so deep in tint, as to be nearly black. The dry substance has a 

 slight coppery lustre, like that which indigo possesses when rubbed. It dissolves 

 in water, the solution being of the most gorgeous crimson, becoming rose-coloured 

 by addition of ammonia, while hydrochloric or nitric acids convert it to a scarlet. 

 The colour is tolerably stable, requiring a considerable excess of bromine water 

 to decompose it, the fluid then becoming reddish-brown. 



The crimson liquid undoubtedly contains the sulphate of a new base, apparently 

 a product of oxidation of ethyl-chinoline. The reactions upon which this suppo- 

 sition is founded, are the following : — If solution of potash be added to the crim- 

 son solution, the colouring matter is almost entirely precipitated, and, if the experi- 



