In 1768 he obtained a place in a pharmacy at Stockholm, where he was not allowed any part in laboratory-work. He would make experiments, nevertheless, and so he studied from the windows of the shop the effects of sunlight upon different bodies. He made himself known, too, at Stockholm as a skillful chemist, and formed friendships with the distinguished scientific men of the time. In 1770 he removed to Upsala, where he was installed director of the laboratory-work in a pharmacy, with permission to continue his own experiments.
Forbern Bergman was then Professor of Chemistry in the University of Upsala, and the two men were soon brought into association. Scheele's master had remarked that, on exposing melted saltpeter to a continuous heat, a salt is developed which, on adding acetic acid, gives out red vapors. Neither the chemist Bergman nor the mineralogist Gahn could explain the phenomenon. Scheele had an explanation. He said that the heated saltpeter absorbed phlogiston (is reduced, as we would have it), and gave the salt of a new acid (nitrous acid), which is weak, and can be expelled by acetic acid. Gahn told Bergman of this explanation, and he sought an introduction to the young pharmacist. Thus was laid the foundation of a lasting friendship and co-operation between the two.
In 1775 Scheele obtained the direction of the pharmacy of Köping, whose proprietor had just died, leaving the concern to his widow. This gave him a more comfortable subsistence than he had enjoyed before, although his task in keeping the establishment in good condition and paying up its debts was hard enough. Yet he wrote to one of his friends at about this time: "You may think, perhaps, that material cares are going to absorb me, and take me away from experimental chemistry. Not at all! That noble science is my ideal. Be patient, and you will soon have something new to learn." He was much annoyed about six months afterward by some one coming to buy the pharmacy, and offers of other positions came to him from every side, among them an offer of the superintendency of a distillery, and invitations to Stockholm, Berlin, and London, with salaries that would have been tempting to common men. But the people of Köping said that they would have no pharmacist but Scheele; and he declined all the invitations, saying: "I can not do more than eat my meat; if I can do that at Köping, I need not seek it elsewhere"; and, in reference to an offer which had been made to him from Berlin: "After mature reflection, I decline it. I lack considerably of being as far advanced in chemistry as such a position requires, and I am persuaded that I shall find my daily bread even at Köping."
During his residence at Köping he only gave himself a single vacation, when he went to Stockholm to attend a meeting of the Swedish Academy of Sciences, of which he had been elected a member in 1775. It was the only meeting of the Academy he ever attended, although nearly all of his papers were published in its proceedings.
