310 



CATALOGUE. — PH-YSICAL OPTICS. 



The separation appears to be greatest when the rays pass 

 most transversely with respect to the axis ; hence it may be 

 inferred that this is an unusual refraction. 



Rochon's artificial doubling spar. Goth. 

 Mag. I. 184. 



Plates of different densities cemented together. 



fHaiiy on the double refraction of Iceland 



crystal. A. P. 1788^ 34. 

 Haiiy on double refractions. Ann. Ch. XVII. 



140. 

 Haiiy on the double refraction of sulfur. B. 



Soc. Phil. n. 16. Ph. M. I. 221. 

 Haiiy Traite de phys. II. 347. 



Thinks that the carbonate of lime, and the sulfate, have 

 unusual refractions, because they are composed of obliquan- 

 gular parallelepipeds: other crystals have only the usual 

 refraction, being derived from rectangular forms. 



Haiiy on double refractions, noticed. Ph. M. 



VI. ISl. 

 Ph. tr. 1797. 352. 



Brougham denies the polarity of the particles of light 

 with respect to Iceland crystal. 

 Linck on double refraction. Crell Ann. 



1797. vii. B. B. 



Extr. Ann. Ch. XXVIII. 84. 

 Hind. Arch. II. 74. 



" Kramp attributes the double refraction to reflection from 

 the sides of a primitive crystal, and appears to be fully sa- 

 tisfied with the explanation. 



*Wo]laston on the oblique refraction of Ice- 

 land crystal. Ph. tr. 1802. 381. Nich. 8. 

 IV. 148. 



Narci on the optical properties of rocTi cry- 

 stal. Ph. M. XIV. 306. 



A certain prism cut out of it simply changes right to left, 

 without displacing the image : this must be from some re- 

 flection. Y. 



Diffraction and Irradiation, as af- 

 fecting Astronomical Observations. 



See Eclipses. 



Legentil on the apparent diameter of the sun. 

 A. P. 1755. 437. H. 93. 



Distinct marks of an atmosphere, or ol inflection, or of 

 both,inthe transitofVenus, 1769. ' 

 Legentil on the apparent magnitude of 

 opaque bodies. A. P. 1784. 469. 



Observes, that it is diminished 5" or 6" when they are- 

 viewed on a light ground : from experiments on a parallel- 

 ogram enlightened half behind and half before: and on two 

 contiguous images of circles. 



Maskelyne. Ph. tr. 1768. 355. 



Dunn's figure of the appearances of Venus, 

 on the sun. Ph. tr. 1770. 60. 



Lalande 6n the elongation of the disc of Ve- 

 nus in the transit. A. P. 1770. 406. H. 

 80. 



Says, that the aberrations of the rays of light in the te- 

 lescope make the sun's diameter appear too large by 

 about 6". 



A. P. 1775. 265. 



Dionis du Sejour attributes an inflection of about 5* to 

 the refraction of the lunar atmosphere. Observes, that a star 

 appears to enter on the moon's disc in an occultation. 

 A. P. 1780. 237. 



Dionis da Sejour considers a solar irradiation of 3"i, and 

 a lunar inflection of the same quantity, as absolutely de- 

 monstrable. 



Herschel. Ph. tr. 1783. 4. 



A light circle being viewed, together with a dark one 

 placed on a light ground, the light circle appears the 

 larger. 



Irradiation is generally, and perhaps always, an afiicction 

 of vision, but perhaps it may sometimes be occasioned by 

 a deviation of light from a direction perfectly rectilinear, 

 and its effects are not any time easily distinguished from 

 those of diffraction. 



See Telescopes. 



Vision in general. 



Fabriciiis ab Aquapendente de visione. f. 



Ven. 1600. M. B. 

 De Dominis de radiis visus et lucis. 

 Scheinerioculas. 4. Rom. 1652. M. B. 

 Trarer nervus opticus, f. Vienn. 169O. 

 Berkeley's theory of vision. &. Dubl. 1709. 



M.B. 



