The Romance of Modern Chemistry

GREAT DISCOVERIES The difficulty is that people sometimes make a valuable observation without attaching importance to it. It may be difficult to bring their new discovery into harmony with what they already know, and so they come to the conclusion that their observation must have been wrong, and that their senses must have deceived them ; or else, by some forced explanation, they seek to fit the newly observed facts into some of the mental pigeon-holes which are already available. When such difficulties crop up, the remedy is to have recourse to fresh observation and to collect more facts. In this connection there is an interesting story of Liebig, whose fame as a chemist rests on many other things than extract of meat. On one occasion he pre- pared a liquid which in many of its properties resembled chloride of iodine, although in other respects quite different. He was struck by the differences, but, without making any further experiments, devised an explanation which satisfied him at the time. He was at least sufficiently satisfied to label the bottle of liquid “ chloride of iodine.11 The reader can imagine Liebig’s disappoint- ment and chagrin a few months later when he heard of the discovery by a Frenchman of the new element “ bromine,” and realised that it was this element which he had had before his eyes all the time and had labelled “chloride of iodine.” Liebig tells the story himself, and quotes it as showing the result of adopting explana- tions not founded on experiment. As an example of the persistent and successful follow- ing up of puzzling observations by further experiments, nothing better can be quoted than the work which led to the discovery that there was in atmospheric air a gas, the presence of which had not previously been 340