382 ___________________________________________________________________________________________________________ THE COLLIERY GUARDIAN February 23, 1917. certain amount of bibliographic knowledge through being a member of the British Association Committee on Fuel Supplies. Really, the amount of absolute know- ledge of the constitution of coal which had yet been obtained was -almost negligible. It was certainly no greater than it was in 1908, after Dr. Bedson published the results of his experiments on the exhaustion of coal by pyridine. The only new step seemed to be Dr. Wheeler’s extraction of the pyridine extract by chloro- form, in which he did seem to have shown that that pyridine extract was composed of two separate parts. He thought the relation of the portion insoluble in pyridine to the portion soluble in pyridine but not in chloroform was a question that very much required examination. Messrs. Parr and Hadley, of the Univer- sity of Illinois, had done some interesting work, which seemed to have been very elaborate and careful. They examined a great many of their local coals with the aid of phenol, but, generally, the results of their phenol extractions corresponded with the results Dr. Bedson obtained with pyridine. There was very little difference in the ultimate analyses. There were certain differ- ences in the behaviour of the two when subjected to destructive distillation, but no definite information was got, and the American experimenters very wisely refrained from drawing any deductions as to the nature of the compounds from which that part of coal was derived. The speaker thought that Dr. Wheeler stated something to the effect that none of the hydrocarbons which were obtained by distillation from coal existed in the coal. itself. That was quite contrary to the result of the work of Pictet to which Dr. Smythe had referred. Pictet distilled coal at as low a temperature as he could obtain, and obtained some tar from which he got a number of hydrocarbons running between C8 and C13. When he then extracted a raw coal with benzene, he obtained from it hydrocarbons which were identical with those he had obtained from the tar; and, therefore, he assumed that they had simply distilled in his low- temperature vacuum distillation. As to Dr. Stopes’ paper, it seemed to him that Dr. Stopes was going on the right lines in proposing to investigate microscopic- ally, not only -the coal, but the products of coal obtained by solution in pyridine and other solvents. Mr. S. H. Collins, Lecturer in Agricultural Chemistry, Armstrong Colege, said pyridine seemed a double-barrelled sort of extractor ; not merely, something that would extract resins, but that would extract any- thing that was likely to be acidic in nature. The authorities all seemed to hang about the idea that humic bodies were present, and anything of any alkaloid char- acter would tend to extract these. Coal was a very curious thing, because there were some instances in which coal made quite a good soil, and other cases where it certainly made an extraordinarily bad one, and he did not quite know what it was that made the difference. The best soils produced from coal were generally from the type of coal one would not want to burn—coal with a fearful lot of ash, and that sort of thing. Dr. Bedson said Mr. Collins was perfectly right in his view of pyridine. He (Dr. Bedson) was very much entranced with pyridine in the first instance, because it did so much; but it did rather too- much for the pur- pose, and he thought the proper method of applying it would be to use, first, as many resinic solvents as one could employ — and there, were some coming on the market now with which he was making some experi- ments, and perhaps at some future date in the next decade he might be able to say something about the results—and afterwards to treat the coal with pyridine. He did not know that Dr. Wheeler was altogether justified in distinguishing between resinic and cellu- losic constituents. Besides the vegetable origin of coal, they had to consider the animal remains present, from which, he dared say, some of the nitrogen came; and it was rather lumping things together to divide them into resinic and cellulosic constituents. That was o subject that had interested him for many years now. He felt ashamed that there was so little that one could report upon with any degree of certainty as to coal. He was very glad to find that whilst, 20 years ago, chemists were rather inclined to regard coal much as the ordinary consumer of coal regarded it, and, beyond that, to take very little interest in it except to use it for distillation purposes, during that period in this country and in France, and, no doubt, in Germany, a very considerable interest had developed in the nature of the compounds that went to form coal. At one time he was 'afraid that, when chemists came to attack coal, there would be none to attack—it would be all used up. Now, however, it seemed to him that there was an army of workers attack- ing coal from different points of view, and the outcome of that must be very 'advantageous to science. Coal was a vast subject, but he supposed that, if they went on pegging away, each doing a little, they might furnish material out of which some committee, collating the results, might draw conclusions which would advance our knowledge of the nature of coal. The Chairman asked whether the resinic matter extracted by pyridine was the matter that bound the coal together when it coked. Dr. Bedson replied that what struck him at the very outset was that the pyridine extract from coking coal •coked readily, but the material that was left ha