Roscoe now elected to follow chemistry as a career, somewhat to the dismay of his relatives, who, he tells us, imagined he intended “to open a shop with red and blue glass bottles in the window,” such being the external indications of the calling of a chemist in this country. And no wonder they were perturbed, for any one not being registered as a “pharmaceutical chemist,” or as a “chemist and druggist,” who should presume to style himself a chemist was punishable with a fine. Liebig was not altogether well informed of the facts when he wrote to Berzelius that the English chemists were ashamed to call themselves such because the apothecaries had appropriated the name. It was not so much that they were ashamed as they were actually prohibited by law. Although nearly two generations have passed since those days, it may be doubted whether even now the public mind has quite grasped the distinction between a chemist properly so-called and an apothecary.
Having settled upon his life’s work, Roscoe entered the Birkbeck Laboratory at University College, then under the direction of Williamson, whom Graham had just brought over from Paris, where he had been working with Laurent and Gerhardt. Roscoe had the highest appreciation of the genius and power of Williamson, and pays grateful homage to his memory in the following extract from his Autobiography:
At the time I entered the laboratory Williamson was engaged in the researches which have made his name a household word to chemists all the world over. His was a mind of great originality, and his personality was a most attractive one. And, despite his physical disabilities—for he lost an eye and the proper use of his left arm in early childhood—he was a diligent and accurate worker. Ardently devoted to his science, he infected all who worked under him with the same feeling. And his pupils willingly own that much of the success that they may have met with in after years was due to his teaching and example. I well remember the feelings of interest he aroused as he each day came down to the laboratory brimful of new ideas. First it was his explanation of the theory of etherification, of which he proved the truth by preparing the mixed ethers, thereby ascertaining the general constitution of alcohols and ethers, and laying one of the foundation-stones of modern chemistry. Next it was his well-known paper on the constitution of salts, in which he enunciated principles which have since been generally adopted. Then came his views on atomic motion and interchange, the first definite statement of a series of chemical phenomena which in the hands of Van ’t Hoff and others have become of the highest import.… He clearly foresaw the principles upon which the modern development of the steam-engine depends, and though he failed for want of constructive skill, he pointed the way which engineers have since followed with conspicuous success.