Karl Wilhelm Scheele is the most famous of pharmacists, and has few
equals in scientific history. He was the seventh child of a merchant at
Stralsund, then in the possession of Sweden, and was born on December
9th, 1742. He had a fair education and at school was diligent and apt
in acquiring knowledge. If he was born with a gift, if his genius was
anything more than an immense capacity for taking pains, this aptness
was the faculty which distinguished Scheele from other men. He made
thousands of experiments and never forgot what he had learned from any
one of them; he read such scientific books as he could get, and never
needed to refer to them again. His friend Retsius, a pharmacist like
himself as a young man, but subsequently Director of the Museum of
Lund, has recorded Scheele’s remarkable power in this respect. “When he
was at Malmö,” he writes (this was when Scheele was about twenty-four
years of age), “he bought as many books as his small pay enabled him to
procure. He would read these once or twice, and would then remember all
that interested him, and never consulted them again.”
[Illustration: KARL WILHELM SCHEELE.]
An elder brother of Karl had been apprenticed to an apothecary at
Gothenburg, but had died during his apprenticeship. Karl went to this
apothecary, a Mr. Bauch, as apprentice at the age of fourteen, and
remained there till Bauch sold his business in 1765. Then he went to
another apothecary named Kjellström at Malmö. Three years later he was
chief assistant to a Mr. Scharenberg at Stockholm. His next move was
to Upsala with a Mr. Lokk, who appreciated his assistant and gave him
plenty of time for his scientific work.
Lastly, he took the management of a pharmacy at Köping for a widow
who owned it, and after an anxious time in clearing the business from
debt, he bought the business in 1776 and for the rest of his short life
was in fairly comfortable circumstances. Ill-health then pursued him,
rheumatism and attacks of melancholy. In the spring of 1786, in the
forty-fourth year of his age, after suffering for two months from a
slow fever, he died. Two days before his death he married the widow of
his predecessor, whose business he had rescued from ruin, so that she
might repossess it. A few months later she married again.
That was Scheele’s life as a pharmacist; patient, plodding,
conscientious, only moderately successful, and shadowed by many
disappointments. The work he accomplished as a scientific chemist
would have been marvellous if he had had all his time to do it in;
under the actual circumstances in which it was performed it is simply
incomprehensible. A bare catalogue of his achievements is all that can
be noted here, but it must be remembered that he never announced any
discovery until he had checked his first conclusions by repeated and
varied tests.
[Illustration: SCHEELE’S PHARMACY AT KÖPING.]
An account of an investigation of cream of tartar resulting in the
isolation of tartaric acid was his first published paper. He next
made an examination of fluor-spar from which resulted the separation
of fluoric acid. From this on the suggestion of Bergmann he proceeded
to a series of experiments on black oxide of manganese which besides
showing the many important combinations of the metal led the chemist
direct to his wonderful discoveries of oxygen, chlorine, and barytes.
This work put him on the track of the observations set forth in his
famous work on “Air and Fire.” In this he explained the composition of
the atmosphere, which, he said, consisted of two gases, one of which he
named “empyreal” or “fire-air,” the same as he had obtained from black
oxide of manganese, and other substances. He realised and described
with much acuteness the part this gas played in nature, and the rest of
the book contained many remarkable observations which showed how nearly
Scheele approached the new ideas which Lavoisier was to formulate only
a few years later. “Air and Fire” was not issued till 1777, three
years after Priestley had demonstrated the separate existence and
characteristics of what he termed “dephlogisticated air.” But it is
well known that the long delay of Scheele’s printer in completing
his work was one of the disappointments of his life, and there is
evidence that his discovery of oxygen was actually made in 1773, a
year before Priestley had isolated the same element. Both of these
great experimenters missed the full significance of their observations
through the confusing influence of the phlogiston theory, which neither
of them questioned, and which was so soon to be destroyed as the direct
result of their labours.
Among the other investigations which Scheele carried out were his
proof that plumbago was a form of carbon, his invention of a new
process for the manufacture of calomel, his discovery of lactic, malic,
oxalic, citric, and gallic acids, of glycerin, and his exposition of
the chemical process which yielded Prussian blue, with his incidental
isolation of prussic acid, a substance which he described minutely
though he gives no hint whatever to show that he knew anything of its
poisonous nature.
The subjects mentioned by no means exhaust the mere titles of the work
which Scheele accomplished; they are only the more popular of his
results. The value of his scientific accomplishments was appreciated
in his lifetime, but not fully until the advance of chemistry set them
out in their true perspective. Then it was realised how completely and
accurately he had finished the many inquiries which he had taken in
hand.