1871.] History of the Opium Alkaloids. 375 



precipitate, which rapidly darkens, and finally turns a deep green, nearly 

 olack. Dried at 100° rapidly, the product gave the following numbers, 

 which fall below those required for the formula C 72 H 83 Br N 4 12 , hut 

 which agree with those required for a similar formula but containing 

 more oxygen : — 



0*3810 grm. gave 0'8460 C0 2 and 0*2080 H 2 0, 



0-4430 grm. boiled with AgN0 3 andN0 3 H gave 0'059 AgBr. 



Calculated Found. 



C 72 864 60-89 60-56 



H 83 83 5-85 6-07 



Br 80 5-64 .... 5'67 



N 4 56 3-95 



21 336 23-67 



C 72 H 83 BrN 4 12 +0 9 1419 lOO'OO 



It hence appears that the free base rapidly absorbs oxygen. In confir- 

 mation of this, 0*11 grm. of the hydrobromate treated with caustic potash 

 and injected by a pipette into 15 cubic centims. of air over mercury ab- 

 sorbed 0*9 cubic centim. in the course of an hour, or 6 per cent, of the 

 total volume of the air ; the salts, however, when dry, may be kept without 

 alteration, and only slowly darken by exposure to air when moist. 



This welding together of four molecules is not wholly without parallel 

 in the history of the opium alkaloids ; and their derivatives thus opianic 

 acid heated * furnishes a body containing four times as much carbon as the 

 original acid ; thus 



4C 10 H 10 O 5 =H a O + C 40 H, 8 O lfl . 



The qualitative reactions of bromotetracodeia appear to be identical with 

 those of bromo- and chlorocodide. The base itself, when freshly precipi- 

 pitated, is slightly soluble in water, being thrown down again by addition of 

 strong brine ; in ether and benzol it is almost insoluble, and in alcohol but 

 sparingly soluble. 



When crude bromotetracodeia, got by extraction with ether of the mix- 

 ture of bases thrown down by carbonate of soda, is dissolved in weak hydro- 

 chloric acid, and precipitated twice or thrice by excess of stronger acid, 

 nearly white flakes are ultimately obtained, resembling in all their physical 

 properties the bromohydrobromate of tetracodeia. These flakes, however, 

 contain no bromine, the absence of this element being ascertained by the ne- 

 gative results obtained on examining with chlorine-water and ether the 

 acidified solutions of the lime-salts got by combustion with quicklime, and 

 of the sodium-salts got by boiling with N0 3 H and AgN0 3 , and fusing 

 with carbonate of soda the silver-salts thus got. Dried over S0 4 H 2 and 

 finally at 100°, this body gave numbers indicating a base of constitution 



* Matthiessen and Wright, Proc. Koy. Soc, vol. xvii. p. 341. 



