590 PROFESSOR ANDERSON ON THE PRODUCTS OF THE 



as that developed on the wood itself. When agitated with cold dilute acids, pyrrol 

 dissolves unchanged, but on heating the solution, it deposits a red flocky sub- 

 stance, and if not too dilute, the whole is converted into a gelatinous mass, so that 

 the vessel may be inverted without anything escaping. The same change takes 

 place in the cold, when the acid solution is kept for some days. When bichloride 

 of platinum is added to a cold hydrochloric solution of pyrrol, it instantly becomes 

 dark coloured, and in the course of a few minutes an abundant black precipitate, 

 containing platinum, is deposited. When boiled with sesquichloride of iron, the 

 solution becomes first green, and finally black. Bichromate of potash also de- 

 composes it with the formation of an abundant black precipitate, and sulphate 

 of copper, when heated with it for some time, acquires a green colour, and a small 

 quantity of a black powder is deposited. It is rapidly oxidized by nitric acid, 

 with the evolution of abundant red fumes, and formation of a dark-red solution, 

 which, when diluted, permits a yellow resin to fall. By long-continued ebullition, 

 oxalic acid is produced. An alcoholic solution of pyrrol gives white precipitates 

 with corrosive sublimate and chloride of cadmium, but it does not precipitate the 

 metallic oxides generally. 



The combustion of pyrrol was very easily effected, and the results are sub- 

 joined. The first six analyses were those of crude or fetid pyrrol, and are all from 

 different preparations except the first two. The last is that of the fragrant 

 pyrrol. 



(5 1 805 grains of pyrrol gave 

 15-250 ... carbonic acid and 

 4-070 ... water. 



(3-675 grains of pyrrol gave 

 9*625 ... carbonic acid and 



2-550 ... water. 



{5-250 grains of pyrrol gave 

 13*830 ... carbonic acid and 



3-675 ... water. 



{4*033 grains of pyrrol gave 

 10590 ... carbonic acid and 

 2-922 ... water. 



{4*706 grains of pyrrol gave 

 12345 ... carbonic acid and 



3-307 ... water. 



{5*280 grains of pyrrol gave 

 13 - 845 ... carbonic acid and 



3-676 ... water. 



{5*213 grains of fragrant pyrrol gave 

 13 675 ... carbonic acid and 



3*649 ... water. 



