[1] The numbers, as usual, indicate the corresponding paragraphs in the original.
[2] In the historical part, Goethe has to speak of so many followers of Newton who begin their statements with "Si per foramen exiguum," that the term is a sort of by-word with him.
[3] At mid-day on the 24th of June the author observed the white cross reflected from every part of the horizon. At a certain distance from the sun, corresponding, he supposes, with the extent of halos, the black cross appeared.
[4] Whence the term entoptic.
[5] Before described: the author describes several others more or less complicated, and suggests a portable one. "Such plates, which need only be an inch and a quarter square, placed on each other to form a cube, might be set in a brass case, open above and below. At one end of this case a black mirror with a hinge, acting like a cover, might be fastened. We recommend this simple apparatus, with which the principal and original experiment may be readily made. With this we could, in the longest days, better define the circle round the sun where the black cross appears," &c.
NOTE T.—[Par. 496.]
"Since Goethe wrote, all the earths have been decomposed, and have been shown to be metallic bases united with oxygen; but this does not invalidate his statement."—S. F.
NOTE U.—[Par. 502.]