504 [March 26, 



of free hydrochloric acid. Alkalies, or alkaline carbonates or sul- 

 phites, throw down from the aqueous or acid solution an orange- 

 coloured granular precipitate (cotarnamic acid?) free from hydro- 

 chloric acid ; this precipitate dissolves in excess of alkali, giving a 

 solution which quickly becomes dark brown by exposure to air ; with 

 hydrochloric acid, it regenerates the original crystalline compound ; 

 it dissolves slightly in water, with a bright orange colour that is visi- 

 ble even in very dilute solutions. The slightly acidulated solution 

 of the hydrochlorate is pale yellow when pure, but acquires a deep- 

 green colour in the air. A few drops of nitric acid added to a hot 

 solution cause it to appear of an opake crimson colour by reflected 

 light, though the liquid is still transparent when examined by trans- 

 mitted light. Nitrate of silver added in quantity more than sufficient 

 to precipitate the chlorine is quickly reduced. The compound ac- 

 quires a fine crimson colour when evaporated nearly to dry ness on 

 the water-bath, with a slight excess of dilute sulphuric acid. 



Hydriodic and diluted sulphuric acids decompose cotarnine at a 

 high temperature in the same way as hydrochloric acid. The products 

 so formed have not been isolated, but were converted into hydro- 

 chlorate of cotarnamic acid. 



The authors conclude by offering some suggestions towards the 

 interpretation of the results they have obtained. Only the most 

 important points discussed by them will be briefly indicated here. 



They suppose that when opianic acid is converted into meconin 

 by the action of nascent hydrogen, or into meconin and hemipinic 

 acid by the action of potash *, a substance containing G 10 H 12 O 3 may 

 possibly be the immediate product of the reaction, and that this 

 body bearing the same relation to meconin that glycol, 2 H 6 O 2 ,does 

 to oxide of ethylene, 2 H* O, or mannite, C 6 H 14 O 6 , to mannitan, 

 C 6 H 12 O 5 may give rise to meconin by subsequent loss of the 

 elements of water. Making this supposition, the two reactions in 

 question may be represented by the equations 



(1) ... 10 H 10 O 5 + H 2 = .G 10 H 12 O 5 



Opianic acid. Hypothetical hydrate 



of meconin. 



(2) ... 2( 10 H 10 O 5 ) + H 2 O = 10 H 12 O 5 + 10 H 10 O 6 



Opianic acid. Hypothetical Hemipinic 



hydrate of meconin. acid. 



* Proc. Roy. Soc. vol. xi. p. 57. 



