‘288 
DR. BREWSTER ON THE PHENOMENA AND LAWS 
tioned*. Immediately after this I received the most perfect plates of silver, 
one pair polished by friction, and another by hammering ; two pair of plates 
of gold, one of jewellers’, and another of fine gold ; with plates of steel, plati- 
num, palladium, copper, brass, and speculum metal ; and with their help I 
obtained the general result, that a single reflexion from a metallic surface pro- 
duces the same effect upon polarized light as a certain thickness of a crystal- 
lized body, with many other results, which it is unnecessary here to indicate. 
As soon as M. Biot had received notice of my discovery, he seems to have 
devoted himself to the same inquiry; and with all the leisure of an Academician, 
and the splendid apparatus presented to him by the Institute, he obtained many 
of the results at which I had arrived, and others to which I have no claim ; 
and on the 29th of March he transmitted to me, through Dr. Wollaston, an 
open letter containing an abstract of his experiments, and expressing the hope 
that they would be of use to me in my researches. 
Although this expression led me to believe that I should enjoy the privilege 
of publishing the first account of my own discovery, yet I took the precaution 
of having all my papers on the subject signed by the Treasurer of the Royal 
Society of Edinburgh, and I proceeded with new zeal in the further examina- 
tion of the subject. I soon learned, however, from M. Biot, that he meant to 
treat the subject in his Trait6 de Physique ; and though I remonstrated against 
this as a breach of courtesy, I had the mortification to see the discovery, to 
which I perhaps attached too much importance, published for the first time in 
a foreign work. 
I trust the Society will excuse these details as a necessary apology for having 
so long delayed to fulfil the promise, more than once made in their Trans- 
actions, to communicate to them an account of these experiments -f-. The 
* It is related in the History of Optics, Edinburgh Encyclopaedia, vol. xv. p. 493, note, that I com- 
municated this discovery to M. Biot on the day on which it was made: — this is a mistake, as it was 
done a month afterwards. 
f In a letter to Sir Joseph Banks, dated July 28th, 1815, I communicated an abstract of these 
and other experiments, with a request that he would permit the MS. to remain in his possession, as 
an evidence of my claims. Sir Joseph complied with this request : but nearly two years afterwards, 
happening to see the MS., he thought that it had been intended for publication, and laid it before the 
Royal Society without my knowledge. It was accordingly read on the 23rd of January 1817, under 
the title of Abstract of Experiments on Light, and ordered to be printed. When the proof-sheet was 
sent me for correction, I requested the paper to be cancelled, as it was not intended for publication. 
