192 MR JAMES DEWAR ON THE OXIDATION PRODUCTS OF PICOLINE. 



platinum salt, and a fractional crystallisation made. The platinum was deter- 

 mined in these different salts as follows : — 



1st Crystallisation— 0' 177 grm. pt-salt gave 0'077 grm. pt=43'7 per cent. 

 2d „ -0-6910 „ „ 0-2102 „ =33-95 per cent. 



The first sample agreed in composition with the double chloride of platinum 

 and ammonium ; the second, with that of a mixture of the double platinum salts 

 of pyridine and picoline. There was produced by the reaction, therefore, 

 carbonic, nitric, oxalic, acetic, and a complex of new acids, ammonia, and pro- 

 bably a small quantity of pyridine. The relative proportion of the products 

 obtained depended on the quantity of the oxidising agent used, the volume of 

 the solution, rapidity of the action, and the quantity of bases present in the field 



of action. 



( CO IT 



Di-carbo-pyridenic Acid C 5 H 3 N < nr) tj- — The crystalline acid substance 



separated by adding excess of sulphuric acid to the concentrated alkaline fluid, 

 after standing overnight was collected on a filter, and repeatedly crystallised 

 from hot water (in which it was easily soluble) until free from oxalic acid and 

 potassium salts. When first separated from the acid solution it appeared in 

 long needles ; but after several recrystallisations from water it was obtained in 

 the form of perfectly colourless plates, resembling naphthaline. (The crystallo- 

 graphic constants of this acid have not yet been determined.) The crystals 

 did not contain any water of hydration. The following are the results of the 

 analyses of the acid and its silver salt : — 



Acid. 



Weight of acid taken, ......... - 2195 grm. 



Carbonic anhydride produced, ....... 00685 „ 



Water produced, ......... 0'4040 „ 



Nitrogen found by Gottlieb's method to bear to the C0 2 produced, the 



proportionate vol. of, . . . . . . . 1 to 14'2 



Calculated centesimally these figures give — 



Sample. C 7 H 5 NO.. 



Carbon, ... 50d9 50"29 



Hydrogen, 347 2'99 



Nitrogen, .......... — — 



Silver Salt." 



As with the acid, the salt was dried at 100° C. 



Weight of salt taken, ...... 



Carbonic anhydride produced, .... 



Water produced, ...... 



Weight of salt taken, ...... 



Silver obtained, ....... 



* I. and II. were samples of silver salts obtained from different experiments. I. was got by double 

 decomposition of the sodium salt ; II. from the ammonium salt. 



I. 



0-8766 grm. 

 0-6985 „ 

 0-0554 „ 



II. 

 0*5456 grm. 

 0-4518 „ 

 0-0602 „ 



0-6980 grm. 

 1-5111 „ 



0-3951 grm. 

 0-6525 „ 



