78 Intelligence and Miscellaneous Articles. 



beyond the red separates into a number of coloured zones of great 

 intensity, presenting violet, indigo, blue, green. All the colours 

 advance one after the other towards the centre of the image, which 

 they successively occupy. 



By varying the brightness of the object, and the length of time of 

 looking at it, I have been able to detect one or two constant series 

 of colours, apparently very different, which these accidental images 

 present. 



'2. When the accidental image is formed in the eyes, if they are 

 opened towards a white surface, the image remains ; but it generally 

 passes from the tint which it has to one of those which it would 

 assume at a later period if the eyes were kept closed, and at the 

 same time the tints which still remain at the border advance more 

 towards the centre, which they occupy successively. The white light 

 which enters the eye has therefore the effect of accelerating the pro- 

 gression of the colours from the circumference to the centre of the 

 image. I have traced this influence of the exterior white light, 

 whether by opening the eyes before a surface more or less lighted, 

 or by gradually opening them, and I have found that the tint to 

 which the image passes is more advanced in the series when the ex- 

 terior light is more intense. 



3. My experiments have enabled me to observe those instances in 

 which the accidental image of a white object passes through alter- 

 nations of brightness and darkness ; I have always observed that the 

 images are coloured. 



In the hope of being able to account for these effects, I have en- 

 tered upon the study of the accidental images produced by coloured 

 objects. This part of the question has been much disputed. I have 

 repeated almost all the experiments described by various authors, 

 and have frequently been astonished at the results which I have ob- 

 tained. I shall describe these in a second memoir. — Comptes Rendtts, 

 Dec. 8, 1851. 



EXTRAORDINARY SPOTS ON THE SUN. 



On Saturday last, the 29th of November, the solar maculae, which 

 have of late been very numerous, assumed a remarkable shape and 

 occurred in very considerable number. Dr. Forster, who has been 

 occupied of late in taking drawings of these spots, observes that he 

 has never seen any spot on the sun's disc so large or unusual in form 

 as that which occurred on Saturday : it was of a long and irregular 

 form, densely black, and surrounded with a widely-spreading greyish 

 margin, as well as by several other smaller macules. Many other 

 more round and compact spots appeared on other parts of the disc. 

 But the most remarkable circumstance was the rapid changes ob- 

 served in these phaenomena. While Dr. Forster was observing them, 

 several new spots broke out into view. 



The connexion of these phaenomena with the abundance of wet 

 and cold were formerly noticed by the late Dr. Herschel. Now that 

 the weather has been dry in England, a more than ordinary quantity 

 of snow and rain has fallen on the Continent. 



Bruges, Dec. 5, 1851. 





