Work on optics Though Brewster duly finished his
theological studies and was licensed to preach, his other interests distracted him from the duties of his profession. In 1799 fellow-student
Henry Brougham persuaded him to study the
diffraction of light. The results of his investigations were communicated from time to time in papers to the
Philosophical Transactions of London and other scientific journals. The fact that other scientists – notably
Étienne-Louis Malus and
Augustin Fresnel – were pursuing the same investigations contemporaneously in France does not invalidate Brewster's claim to independent discovery, even though in one or two cases the priority must be assigned to others. A lesser-known classmate of his,
Thomas Dick, also went on to become a popular astronomical writer. The most important subjects of his inquiries can be enumerated under the following five headings: • The laws of
light polarization by
reflection and
refraction, and other quantitative laws of phenomena; • The discovery of the polarising structure induced by heat and
pressure; • The discovery of crystals with two axes of double refraction, and many of the laws of their phenomena, including the connection between optical structure and crystalline forms; • The laws of metallic reflection; • Experiments on the absorption of light. In this line of investigation, the prime importance belongs to the discovery of • the connection between the refractive index and the polarizing angle; • biaxial crystals, and • the production of double refraction by irregular heating. These discoveries were promptly recognised. As early as 1807 the degree of
LL.D. was conferred upon Brewster by
Marischal College,
Aberdeen; in 1815 he was elected a Fellow of the
Royal Society of London, and received the
Copley Medal; and in 1816 the
French Institute awarded him one-half of the prize of three thousand francs for the two most important discoveries in physical science made in Europe during the two preceding years. In 1821, he was made a foreign member of the
Royal Swedish Academy of Sciences, and in 1822 a Foreign Honorary Member of the
American Academy of Arts and Sciences. Among the non-scientific public, his fame spread more effectually by his invention in about 1815 of the
kaleidoscope, for which there was a great demand in both the United Kingdom, France, and the United States. As a reflection of this fame, Brewster's portrait was later printed in some cigar boxes. Brewster chose renowned
achromatic lens developer
Philip Carpenter as the sole manufacturer of the kaleidoscope in 1817. Although Brewster patented the kaleidoscope in 1817 (GB 4136), a copy of the prototype was shown to London opticians and copied before the patent was granted. As a consequence, the kaleidoscope became produced in large numbers, but yielded no direct financial benefits to Brewster. It proved to be a massive success with two hundred thousand kaleidoscopes sold in London and Paris in just three months. An instrument of more significance, the
stereoscope, which – though of much later date (1849) – along with the kaleidoscope did more than anything else to popularise his name, was not as has often been asserted the invention of Brewster. Sir
Charles Wheatstone discovered its principle and applied it as early as 1838 to the construction of a cumbersome but effective instrument, in which the binocular pictures were made to combine by means of
mirrors. A dogged rival of Wheatstone's, Brewster was unwilling to credit him with the invention, however, and proposed that the true author of the stereoscope was a Mr. Elliot, a "Teacher of Mathematics" from Edinburgh, who, according to Brewster, had conceived of the principles as early as 1823 and had constructed a lensless and mirrorless prototype in 1839, through which one could view drawn landscape transparencies, since photography had yet to be invented. Brewster's personal contribution was the suggestion to use
prisms for uniting the dissimilar pictures; and accordingly the lenticular stereoscope may fairly be said to be his invention. A much more valuable and practical result of Brewster's optical researches was the improvement of the British
lighthouse system. Although Fresnel, who had also the satisfaction of being the first to put it into operation, perfected the
dioptric apparatus independently, Brewster was active earlier in the field than Fresnel, describing the dioptric apparatus in 1812. Brewster pressed its adoption on those in authority at least as early as 1820, two years before Fresnel suggested it, and it was finally introduced into lighthouses mainly through Brewster's persistent efforts.
Other work Although Brewster's own discoveries were important, they were not his only service to science. He began writing in 1799 as a regular contributor to the
Edinburgh Magazine, of which he acted as editor 1802–1803 at the age of twenty. In 1807, he undertook the editorship of the newly projected
Edinburgh Encyclopædia, of which the first part appeared in 1808, and the last not until 1830. The work was strongest in the scientific department, and many of its most valuable articles were from the pen of the editor. At a later period he was one of the leading contributors to the
Encyclopædia Britannica (seventh and eighth editions) writing, among others, the articles on electricity,
hydrodynamics,
magnetism,
microscope,
optics,
stereoscope, and
voltaic electricity. He was elected a member of the
American Antiquarian Society in 1816. In 1819 Brewster undertook further editorial work by establishing, in conjunction with
Robert Jameson (1774–1854), the
Edinburgh Philosophical Journal, which took the place of the
Edinburgh Magazine. The first ten volumes (1819–1824) were published under the joint editorship of Brewster and Jameson, the remaining four volumes (1825–1826) being edited by Jameson alone. After parting company with Jameson, Brewster started the
Edinburgh Journal of Science in 1824, 16 volumes of which appeared under his editorship during the years 1824–1832, with very many articles from his own pen. He contributed around three hundred papers a short popular account of the philosopher's life, in ''
Murray's Family Library'', followed by an 1832 American edition in Harper's Family Library; but it was not until 1855 that he was able to issue the much fuller
Memoirs of the Life, Writings and Discoveries of Sir Isaac Newton, a work which embodied the results of more than 20 years' investigation of original manuscripts and other available sources. Brewster's position as editor brought him into frequent contact with the most eminent scientific men, and he was naturally among the first to recognise the benefit that would accrue from regular communication among those in the field of science. In a review of
Charles Babbage's book
Decline of Science in England in ''
John Murray's Quarterly Review, he suggested the creation of "an association of our nobility, clergy, gentry and philosophers". This was taken up by various Declinarians'' and found speedy realisation in the
British Association for the Advancement of Science. Its first meeting was held at
York in 1831; and Brewster, along with Babbage and Sir
John Herschel, had the chief part in shaping its constitution. Of a high-strung and nervous temperament, Brewster was somewhat irritable in matters of controversy; but he was repeatedly subjected to serious provocation. He was a man of highly honourable and fervently religious character. In estimating his place among scientific discoverers, the chief thing to be borne in mind is that his genius was not characteristically mathematical. His method was empirical, and the laws that he established were generally the result of repeated experiment. To the ultimate explanation of the phenomena with which he dealt he contributed nothing, and it is noteworthy although he did not maintain to the end of his life the corpuscular theory he never explicitly adopted the wave theory of light. Few would dispute the verdict of
James David Forbes, an editor of the eighth edition of the
Encyclopædia Britannica: "His scientific glory is different in kind from that of
Young and Fresnel; but the discoverer of the law of polarization of biaxial crystals, of optical mineralogy, and of double refraction by compression, will always occupy a foremost rank in the intellectual history of the age." In addition to the various works of Brewster already mentioned, the following may be added: ''Notes and Introduction to Carlyle's translation of Legendre's Elements of Geometry
(1824); Treatise on Optics
(1831); Letters on Natural Magic
, addressed to Sir Walter Scott (1832) The Martyrs of Science, or the Lives of Galileo, Tycho Brahe, and Kepler
(1841); More Worlds than One'' (1854). and he described for the first time the red fluorescence of
chlorophyll.
History of Scottish Freemasonry As well as his many scientific works and biographies of notable scientists, Brewster also wrote
The History of Free Masonry, Drawn from Authentic Sources of Information; with an Account of the Grand Lodge of Scotland, from Its Institution in 1736, to the Present Time, published in 1804, when he was only 23. The work was commissioned by Alexander Lawrie, publisher to the
Grand Lodge of Scotland, to whom the work has been, frequently, mis-attributed. Given that the book bears Lawrie's name and not Brewster's this is understandable. The book became one of the standard works on early Scottish freemasonry although it has been largely superseded by later works. There is no evidence that Brewster was a Freemason at the time he wrote the book, nor any that he became one later.
Opposition to evolution Brewster's Christian beliefs stirred him to respond against the idea of the transmutation of species and the theory of evolution. His opinion was that "science and religion must be one since each dealt with Truth, which had only one and the same Author." In 1845 he wrote a highly critical review of the evolutionist work
Vestiges of the Natural History of Creation, in the
North British Review. which he considered to be an insult to Christian revelation and a dangerous example of materialism. In 1862, he responded to Darwin's
On the Origin of Species and published the article
The Facts and Fancies of Mr Darwin in
Good Words. He stated that Darwin's book combined both "interesting facts and idle fancies" which made up a "dangerous and degrading speculation". He accepted adaptive changes, but he strongly opposed Darwin's statement about the
primordial form, which he considered an offensive idea to "both the naturalist and the Christian." ==Family==