252 On Picoline and its Derivatives. 



the reaction took place more quicklj. The filtrate from the 

 manganese hydrate was treated ^Yith silver nitrate, and the 

 insoluble silver salts decomposed with sulphuretted hydrogen. 

 The mixture of acids obtained dissolved in water with dif- 

 ficulty, and on cooling ci-ystallizcd out in crusts. The acid 

 was again dissolved in hot alcohol, in which it is sparingly 

 soluble, and crystallized. It deposited in microscopic needles. 

 Some of it was transformed into the silver salt, and ignited. 



0'2913 grm. gave 0-6335 grm. of metallic silver = 45-82 

 per cent. 



The molecular weight of the acid, if dibasic, is thus 257. 

 No dicarbopyridenic acid could be discovered among the pro- 

 ducts of oxidation after crystallization. From a scarcity of 

 material it was impossible to obtain enough of the acid giving 

 the salt, the analysis of which is given above, for complete 

 investigation. By the kindness of Professor Ferguson, to 

 whom I have to express my deep indebtedness for kindly 

 supplying to me the material for this research, I have now 

 a larger quantity of lutidine at my disposal, and intend to 

 examine its oxidation products more carefully. It is already 

 certain that lutidine is not convertible into dicarbopyridenic 

 acid by oxidation (that is, by transformation of two methyl 

 into two carboxyl groups) ; and this circumstance, combined 

 with the fact that it is not produced by the reaction 



C, Hj N (COO CH3), = 2CO2 + C, H3 N (CHj)^, 



affords strong presumption that the members of this series 

 do not differ from each other by containing a group of methyl 

 more or less. 



Dipicoline, — ISTearly five years ago Professor Thomas An- 

 derson left bottles containing pyridine and picoline, in which 

 a considerable quantity of sodium had been placed. I opened 

 the bottle containing picoline and sodium in the month of 

 March of the current year. The contents of the bottle formed 

 a yellow opaque mass, of the consistency of sirup, at the 

 bottom of the bottle. The substance enclosed much free 

 sodium, and had a black colour. It was spread out and 

 exposed to air, and in about a month was all of the same 

 yellow colour. This oil was Avashed with water for some 

 days to free it from picoline ; when the smell of that base 

 was no longer perceptible, a quantity of the oil was dissolved 

 in hydrochloric acid ; on addition of platinum chloride, a 

 light buff-coloured precipitate, came down, which, under the 

 microscope, was seen to consist of two different varieties of 

 crystals. On ignition^ it left 27-04 per cent, of platinum, 



