PYRROL, C 4 H 5 N or C 4 H 4 NH, an organic base found in coaltar and Dippel's oil.
Dephlegmation of the vapours arising from such mixtures as coaltar fractions, petroleum and the "wash" of the spirit industry, is very important, and many types of apparatus are employed in order to effect a separation of the vapours.
Mansfield to facilitate the fractionation of paraffin and coaltar distillates, consisted in having a pipe leading from the inclined delivery tube of the still to the still again, so that any vapour which condensed in the delivery tube was returned to the still.
The college to which Hofmann devoted nearly twenty of the best years of his life was starved; the coaltar industry, which was really brought into existence by his work and that of his pupils under his direction at that college, and which with a little intelligent forethought might have been retained in England, was allowed to slip into the hands of Germany, where it is now worth millions of pounds annually; and Hofmann himself was compelled to return to his native land to find due appreciation as one of the foremost chemists of his time.
That date may therefore be reckoned as that of the foundation of the coaltar colour industry, which has since attained such important dimensions - in Germany, however, rather than in England, the country where it originated.