and its Derivatives, 249 



The crystals were easily volatile, both alone and with water- 

 vapour, — and when boiled with potassium permanganate gave, 

 after removal of the manganese, a white precipitate Avith 

 silver nitrate, having all the properties of silver dicarbo- 

 pyridenate. 



' The oil was redistilled with water-vapour ; and the basic 

 portion was transformed into a platinum salt. The portion 

 of the double salt insoluble in water consisted of ammonium 

 platinichloride, and the soluble portion of a mixture of 

 pyridine and ammonium platinichloride, as was proved by the 

 amount of platinum it contained. The percentage of platinum 

 found was 37 '03 ; 34*60 is the amount contained in pyridine 

 platinichloride. 



I had intended to reduce the aldehyde to the alcohol ; 

 but the yield of the former was so small that it would 

 have been useless to attempt it. By far the greater portion 

 of the calcium salt decomposed, with formation of pyridine 

 and ammonia. Had it been possible to obtain the alcohol 

 in sufficient quantity, it might have been reduced to the 

 base with which it is related, having the formula of lutidine. 

 A transformation such as this would have gone far to esta- 

 blish the relation of one member of the pyridine series to 

 the others. 



One method, however, remained. The acid when distilled 

 with soda-lime yields pyridine, thus : 



a H3 N (COOH), + 4kaH0 = C5 H5 N + 2 Wa, CO3 -f 2 H^ 0. 

 Under similar circumstances, the methyl ether might give 

 lutidine, provided lutidine be dimethyl-pyridine ; or a base 

 isomeric with lutidine, w^ere that supposition false. 



To decide this question, methyl-dicarbopyridenate was 

 distilled with soda-lime at a heat approaching to redness. 

 This operation was conducted twice— first with about 2 

 grams of the ether, and the second time with rather more 

 than 5 grams. Hydrogen was evolved with great regularity 

 during the wdiole distillation, no gaseous hydrocarbon being 

 formed, as was proved by analysis. On explosion with 

 oxygen, none of the residual gas w^as absorbable by potash : 

 it consisted of pure oxygen. The distillate had a very strong 

 basic smell. It was redistilled vvith dilute caustic soda, and 

 divided into two portions. Both of these were neutralized with 

 hydrochloric acid, and evaporated to dryness : one of them was 

 mixed with nitric acid, and again evaporated to dryness ; the 

 nitric acid was then expelled by repeated evaporation w-ith 

 hydrochloric acid. Platinum tetrachloride was then added, and 

 the precipitate fractionated. The first portions consisted of 



