An instrument of higher interest, the stereoscope, which, though of much later date (1849-1850), may be mentioned here, since along with the kaleidoscope it did more than anything else to popularize his name, was not, as has often been asserted, the invention of Brewster.
His object was to popularize among his countrymen the astronomical theories of Descartes; and it may well be doubted if that philosopher ever ranked a more ingenious or successful expositor among his disciples.
From 1848 to 1887 it was revived, and recently further attempts have been made to popularize the pageant.
Nigra was sent to Paris again to popularize a Franco-Piedmontese alliance, Nigra being, as Cavour said, "the only person perhaps who knows all my thoughts, even the most secret."
The doctrine of the circulation of the blood, which Descartes adopted from Harvey, supplied additional arguments in favour of his mechanical theory, and he probably did much to popularize the discovery.
Nothing indeed did so much to popularize the new doctrines in Poland as this beneficial revival of the long-negle-ted vernacular by the reformers.