324 
Proceedings of the Royal Society 
labours and liberality of Mr Allan, be bad tbe good fortune, at a 
later period, to bring to Edinburgh, and receive under bis roof for 
^ nearly four years, a young G-erman mineralogist of very uncommon 
acquirements. William Haidinger, a native of Vienna, wbo bad 
studied mineralogy at G-ratz under tbe celebrated Frederick Mobs, 
came to Edinburgh in 1823, and resided with Mr Allan till 1826, 
when he returned to Austria, where be prosecuted with ardour bis 
geological and mineralogical studies, and where he now occupies a 
high place in tbe scientific institutions of Vienna. 
During bis residence in Edinburgh, be published several valuable 
papers in our Transactions, and delivered a course of lectures on 
crystallography, at which Dr Edward Turner and other two friends 
were the audience. In claiming to have been one of his pupils at 
these lectures, I cannot resist the gratification of claiming him as 
a pupil in that branch of optics, connected with mineralogy, which 
was then ardently studied in every part of Europe. When Mr 
Haidinger returned to Vienna, he prosecuted the study of physical 
optics with great zeal and success, and had the good fortune to 
discover one of the most beautiful facts in that branch of science. 
He was the first who observed that curious property of the eye by 
which it discovers polarised light, and even the plane of its polari- 
sation, without any instrument whatever. The cause of this re- 
markable phenomenon, called “ Haidinger’s brushes,” has not been 
discovered ; but there is reason to believe that it is produced by a 
structure in the retina, immediately behind the foramen centrale. 
Although the financial state of the Society was greatly improved 
by the increase in the number of its members, yet its funds were 
quite inadequate to defray the necessary expenses of such an in- 
stitution. The annual grant, therefore, of L.300, given in 1836 by 
the Grovernment of Lord Melbourne, though it enabled the Society 
to pay the rent of its apartments, left nothing for those special^ 
objects which such institutions are expected to promote. When 
we consider that the Eoyal Society of London has an annual grant 
of L.IOOO, with free apartments in Burlington House, and a sum 
for the royal medals, we can hardly doubt that an earnest repre- 
sentation to the G-overnment would obtain for us a similar, though, 
doubtless, a smaller grant. 
One of the most effective means by which a society like ours can 
