COLLIDIN ISOMEB. 257 



strong benumbing (vireuse) odor, and is but slightly soluble in water. 

 It is soluble in methyl and ethyl alcohol, ether and acetone. Its 

 density is 0.9865. When dried over potash it boils at 202° 

 without undergoing decomposition. On exposure to the air it be- 

 comes brown, hydrates rapidly, and the boiling point is then lowered. 

 It has not been noticed to absorb carbonic acid from the air. It 

 resembles some of the bases obtained from Dippel's oil. The salts 

 are in general less stable than those of the pyridin bases, and in this 

 respect it approaches the dihydro-pyridin bases. 



On treatment with hydrogen peroxid it yields an isomer of my- 

 din, CgHjjNO. The simple and double salts of this hydroxyl deriv- 

 ative which de Coninck (1899) calls coUidone are decomposed by 

 boiling water. 



The hydrochlorid, CjHjjN.HCl, forms white or slightly yellowish 

 radiate masses which are deliquescent and very soluble in water. 

 The hydrobromid, CjHjjN.HBr, resembles it but is less deliquescent 

 and a trifle less soluble in cold water. 



The platinochlorid, (CgHjjN.HCl)2PtCl^, is a dark orange-colored 

 powder which is insoluble, or almost so in cold water, and is a 

 rather stable compound. Boiling water and water at 80° decom- 

 pose it into hydrochloric acid and (CjHjjNCl)jPtClij which is a 

 light-brown powder, insoluble in cold, scarcely soluble in hot water. 



The aurochlorid, CgHuN.HCl.AuClg, forms a light-yellow pre- 

 cipitate. It is quite stable in cold, but very unstable in hot or even 

 warm water. It cannot be modified by withdrawal of hydrochloric 

 acid. 



The base forms two compounds with mercuric chlorid. (CgHjjN. 

 HCl)2HgCl2 crystallizes in small white needles, which are slightly 

 soluble in water and in dilute alcohol, insoluble in absolute alcohol, 

 and on exposure to moist air undergo change. The second com- 

 pound, 2(CjHjjN.HCl).3HgCl2, is obtained by adding an excess of 

 concentrated mercuric chlorid to a concentrated solution of the hydro- 

 chlorid. It forms slightly yellow, somewhat longer needles which 

 are insoluble in the principal solvents, and are likewise changed by 

 atmospheric humidity. 



The iodomethylate, CjHjjN.CHjI, is formed by mixing solu- 

 tions of the base and methyl iodid in absolute ether. It is deposited 

 as a network of fine white needles, which are but slowly altered in 

 the air, and are soluble in absolute alcohol. This solution on the 

 addition of a little potash assumes a dark -red color, which is height- 

 ened by the addition of a little hydrochloric or acetic acid, and de- 

 stroyed by ammonia without any resultant fluorescence. Warmed 

 with excess of moist solid potash it becomes garnet-red in color and 

 gives off an odor resembling that of the dihydropyridins. It thus 

 behaves the same as the pyridin iodomethylates. 



On oxidation with potassium permanganate it yields an acid which 

 17 



