BIBLIOGRAPHY OF HERSCHEL's WRITINGS. 595 



Herschel, W.: Synopsis of the Wraxixcs of— Continued. 



A. D. Vol. p. 



1809 99 294-298 IjI. A Leusmayhclookeduimnasa FrismbeniroundinacircuJar Form. 



299-302 LII. The critical separation of the Colours, xchich takes place at cer- 

 tain Angles of Incidence, is the primary cause of the Xewtonian col- 

 oured Rings between Object-glasses. 



300-301 A comparison of the similarities presented by the phenomena of 

 the rings and those of the bows, modified by a reflecting plate in 

 contact with the effective surface of the prism. 



302 LIII. Remarks relating to the Newtonian alternate Fits of easy Reflection 

 and easy Transmission. 

 [Dated] Slough, near Windsor, December 9, 1808. 

 Plates XII, XIII, XIV. 



1810 100 149 Supplement to the First and Second Fart of the Faper of Fxperimenis for 



Investigating the Cause of Coloured Concentric Rings between Object- 

 glasses, and other appearances of a similar nature. By William 

 Hkrschel, LL. D., F. R. S. Read March 15, 1810. 

 149-150 A statement of the object of this supplement, and a discussion of 



the distinctions between the red and blue bows. 

 151-153 LIV. Supplemental Considerations, which prove that there are two 



primary p)rismatic Botes, a blue one and a red one. 

 154-157 LV. Illustration of the Dependence of the Streaks of both Boies upon 



the critical Separation. 

 157-159 LVI. Illustration of the dependence of Rings, seen in a Prism, upon 



the critical Separation. 

 159-lGl LVII. Remarks on Colours supposed to be produced by thin Flates 

 or Wetlges of Air. 

 A repetition of the experiment of the 39th Article slightly modified. 

 Two slips of plain glass touching at one end were separated at the 

 other by a single fibre of silk. It is concluded that the phenome- 

 non of coloured streaks seen near the lino of contact is so well 

 accounted for by the 35th Article that it Avould not be philosophi- 

 cal to ascribe them to plain surfaces. 

 lGl-163 LVIII. Illustrating Remarks on the Intention of the Uth Figure, ex- 



jMined in the 48th Article of my Faper. 

 1G4-166 LIX. Experiments on the mtilliplying Fower of Surfaces, in contact, 



which modify the form of prismatic Appearances. 

 166-163 LX. Of' the breadth of the Streaks compared to that of the Bows, and 

 the cause why they must take up a broader space than the Bows from 

 ichich they are derived. 

 169-177 LXI. Of the Manner in rchich Rays that are Separated by critical re- 

 flection or Intromission come to the Eye. 

 Plates V, VI. 

 1811 101 269 Astronomical Observations relating to the Construction of the Heavens, 

 arranged for tlie purpose of a critical examination, the re.^ult of ivhich ap- 

 pears to throw some new light on the Organization of the Celestial bodies. 

 By William Hersciiel, LL. D., F. R. S. Read June 20, 1811. 

 33-'> ^'Synopsis of the Contents of this Faper." 



[The following analysis is by Herschel himself and has served as a 



model to us. ] 

 272 Diffused nebulosity exists in great abundance. 



275 Observations of more than one hundred and fifty square degrees of it. 



277 Its abundance exceeds all imagination. , ■ i ,„a^ 



Nebulous matter consists of substances that give out bght, which may 



have many other properties. 



