On Picoline and its Derivatives. 19 



The partially opaque brown solution obtained by mixing 

 strong solutions of nickel and cobalt might, I think, be used 

 for making standards for the purposes of colorimetrical ana- 

 lysis. For instance, the brown solution mixed with a few 

 drops of potassic bichromate cannot be distinguished from 

 Xesslerized ammonia. Probably the tests used to compare 

 the solutions of steel in Eggertz's process for the estimation of 

 carbon might be made in a similar manner. They would 

 haye the advantage of being permanent. 



After the determination of the copper and nickel by the 

 above methods, the zinc is obtained by difference. If lead is 

 present in the alloy, it is separated by the evaporation with 

 sulphuric acid. 



III. On Picoline and its Derivatives. By William Ramsay, 

 Ph.D., Tutorial Assistant of Chemistry in the Glasgow 

 University. 



I 1ST my last memoir (Phil. Mag. Oct. 1877, p. 251) I men- 

 tioned that on oxidizing lutidine with potassium perman- 

 ganate an acid, or a mixture of acids, was obtained, the silver 

 salt of which contained 45 '82 per cent, of silver, corresponding 

 to a molecular weight of 257, assuming the acid to be dibasic. 

 Since that time I have ascertained that the silver salt of the 

 acid giving the above percentage of silver is not a pure com- 

 pound, but a mixture of an acid and a neutral salt of at least 

 two acids of the same formula. 



Oxidation of Lutidine. — About 100 grams of lutidine, 

 C 7 H 9 N, boiling from 152° to 155° C, were oxidized with 

 potassium permanganate in a tinned iron vessel in precisely 

 the same manner as that described for picoline. After com- 

 plete oxidation the manganese oxide was removed by filtra- 

 tion, and the nitrate was distilled to recover unoxidized luti- 

 dine; less had escaped oxidation than was the case with 

 picoline, probably on account of its higher boiling-point, as 

 well as of its being more easily oxidized than its lower homo- 

 logue. The highly alkaline solution of the products of oxi- 

 dation was then evaporated to dryness, and digested with 

 absolute alcohol by means of an apparatus which permitted 

 the hot alcohol continually to drop on the mixture of salts. 

 After three or four days the insoluble residue consisted of 

 nearly pure potassium carbonate, the organic salts having 

 dissolved in the alcohol. The alcohol was then removed by 

 evaporation. The residue had an extremely persistent bitter 

 taste, almost comparable with that of strychnine. It was 

 * Communicated by the Author- 

 C2 



