A reply to Mr. Robin's remarks on the Essay upon distinct and indistinct vision published at the end of Dr. Smith's Complete system of optiks / by James Jurin.
- James Jurin
- Date:
- 1739
Licence: Public Domain Mark
Credit: A reply to Mr. Robin's remarks on the Essay upon distinct and indistinct vision published at the end of Dr. Smith's Complete system of optiks / by James Jurin. Source: Wellcome Collection.
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![[ 3* ] in the plain and ordinary meaning of the words, hut in a new feme which he thought fit to put upon them. I now apprehend, that by the yellow, which Sir Ifaac Newton ranges in the fifth order of colours, is meant, the yellow, which Sir Ifaac Newton ranges in the third order of colours, but which Mr. Robins is pleafed to range in the fifth order. In like manner by the purple in the fifth order, I fuppofe, is meant the purple of the third order; and by the next order to the fifth, is not meant the fixth, nor the fourth of Sir Ifaac Newton, but the fecond •, and by the feventh order is meant the firft of Sir Ifaac Newton. For though Sir Ifaac conftantly numbers the feries or orders of colours from the black fpot outwards, this Gen¬ tleman, without giving any notice of his inten¬ tion, is pleafed to number them the contrary way. A remarkable inftance, if not of his har- dinefs, at leaft of his care and circumfpedtion not to millead his Reader. Before I difmifs this point of the extent of the fit of eafy reflexion, it will not be improper to take notice of a curious obfervation of Sir Ifaac Newton, the folution of which naturally follows from the principle above laid down, that thofe rays are the den left and moft copious, which are tranfmitted in the middle of the fit of eafy tranf- miffion, and the reft are gradually lefs denfe and copious, by how much they are farther re¬ moved from the middle of the fit, at their en¬ trance into the tranfparent fubftance. “ u Nt firft, lays this accurate Obferver, fpeak- “ ing of the black fpot, I thought there had sc been no light reflected from the water in that place.](https://iiif.wellcomecollection.org/image/b30780287_0039.jp2/full/800%2C/0/default.jpg)
