DESTRUCTIVE DISTILLATION OF ANIMAL MATTERS. 593 
Experiment. Calculation. 
a 
Carbon, . 6 ; F ; 23°25 23°50 Ci, 96 
Hydrogen, é é F ‘ 2°19 2:44 Hy 10 
Nitrogen, é é é . spe 6:87 N, 28 
Cadmium, : 3 4 ‘ me 41-12 Cd, 168 
Chlorine, ¥ , F , ane 26:07 Cl, 106-5 
100:00 4085 
This agrees pretty closely with the formula 2 (C,H, N)+3Cd Cl. 
Products of the Decomposition of Pyrrol. 
The decompositions of pyrrol have not led to results as definite as might have 
been anticipated; and I have therefore restricted myself to the examination of 
the red matter produced by the action of acids, and even that has been attended 
with no little trouble and difficulty. 
Pyrrol Red.—This substance, as has already been frequently observed, is 
produced whenever pyrrol is boiled with an excess of acid; but notwithstanding 
the apparently definite nature of the change, itis extremely difficult to obtain it of 
uniform composition. This is due in part to its tendency to retain a small quantity 
of acid, and in part also to the fact that continued boiling produces a farther 
action, attended by the production of a dark colour in the acid liquid. When 
this occurs, the red matter gives very variable results when analysed, and hence, 
owing to the impossibility of ascertaining the exact length of time during which 
the fluid should be boiled to insure complete formation of the red matter, with- 
out going too far, the results of the analyses are by no means as concordant as 
might be desired. After a good many trials, it was found that the most success- 
ful results were obtained in the following manner :—Pyrrol was dissolved with 
the aid of brisk agitation in sulphuric acid diluted with from four to six parts of 
water, and the solution heated over the gas flame, while the flask was constantly 
shaken. As soon as thered matter had separated in distinct flocks, it was thrown 
on a filter and rapidly washed with boiling water, until the acid was almost 
entirely removed, during which process the pyrrol red acquired a slightly brown 
colour on the surface. A small quantity of diluted caustic potash was then 
poured upon the filter, when the product immediately became of a fine orange 
colour, which it retained after having been washed free of potash. 
Pyrrol red is a fine, light, porous substance, with an orange-red colour, which 
becomes slightly brown by exposure to the air, especially when heated. It is in- 
soluble in water, and is not readily moistened by that fluid. It is slightly soluble 
in cold, more so in boiling alcohol; and is again deposited on cooling in amor- 
phous flocks. It is sparingly soluble in ether. Neither acids nor alkalies dissolve 
it, but if boiled with them for some time it is decomposed. Nitric acid oxidizes 
it, with the production of a resinous substance; and if the action be continued for a 
sufficient length of time, oxalic acid is found in the solution. When heated in 
