Sida:Klingenstierna I.djvu/83

Från Wikisource, det fria biblioteket.
Den här sidan har korrekturlästs
79
upptäckten av akromatismen

100 dukater. Avhandlingen är tryckt i Petersburger-akademiens Handlingar för 1762.


Bland de Klingenstiernska familjepapperen finnes i anledning härav följande odaterade skrivelse av Dollond:


I acknowledge that Mr. Mallet when he was in London shewd me a Letter which he had recievd from Mr. Klingenstierna of Upsal, relating to Sir Isaac Newtons Law of Refraction, in which it was evedently demonstrated that such Laws were inconstant with the Nature of things. As soon therfore as I saw reason to doubt of Sir Isaac, I thought it high time to begin to think for myself, and endeavour to find out the truth by Experiment. I therefore immediatly enterd upon the Experiments which I have had the honour to communicate to the Royal Society of London as may be seen in the transactions and by which it appears that Sir Isaac Newton was greatly mistaken in his notion of Refraction. I there shew that I had found two sorts of Glass that diverg’d the Colours very differently in equal Refractions, for the white flint Glass in the same Refraction would diverge the Colours as 3:2 in the Crown. That is if be the ratio of refraction of white flint Glass for the red rays, and the ratio of the violet; also the ratio of refraction of the red rays in crown glass, and that of the violet rays then would , altho the ratio of was no more than 1,015:1. It also appears from these experiments that Mr. Eulers hypothesis is wery far from the Truth, for let the ratio of the red rays in crown glass and that of the violet and let the ratio of the red rays in white flint glass, then according to Mr. Euler will be the ratio of the violet whence if this theorem was true the ratio of the divergency of the colours in equal refractions would be as . But the ratio of the