Royal Academy of Sciences of Paris. 301 



should we not see evidence of its existence, in some shape or other, 

 at every occultation which occurred I yet, how infinitely few are the 

 instances, in which any thing whatever is observable of alteration in 

 the star, on the moon's approach to it j indicated by derangement of 

 its position, diminution of its splendour, or change of colour. Still it 

 must be remembered, such changes do stand on record ; but they are 

 either so unsubstantiated, or are so referable to other causes than a 

 lunar atmosphere, that we are scarcely warranted in lending ourselves 

 to the hypothesis, to which they would conduct us. 



The hypothesis next in order, suggests irradiation as the source 

 from which the anomaly is derived. It seems, however, Mr. South 

 thinks, incapable of answering the purpose for which it is brought 

 forward ; seeing that projections of stars upon the moon's dark 

 limb, have been witnessed by Messier, by Maskelyne, by Arago, by 

 Mathieu, and by himself. 



That the last hypothesis, — namely, that which supposes the appa- 

 rent projection to arise from the different refrangibilities of the rays 

 issuing from the star and moon, — is not tenable, Mr. South advances 

 the circumstance, that not only Aldebaran and the red stars, are 

 liable to the anomaly ; but that stars as remarkable for their white 

 light, as is Aldebaran for its red, have exhibited the phaenomenon of 

 apparent projection. He also says that, as far as he knows, no instance 

 of apparent projection of the planet Mars upon the moon's disk, is at 

 present recorded amongst the list of lunar occultations of that planet j 

 yet Mars is much more decidedly red than Aldebaran, or than any 

 other star which has been observed on the lunar disk. 



Having, as he thinks, shown that the above hypotheses are inade- 

 quate to the purpose for which they have been designed, Mr. South 

 states that he should not be justified in advancing any hypothesis in 

 addition to those which he has combated ; but concludes his paper by 

 stating that from the Connoissance des Terns, he finds that the moon's 

 path will, during the years 1829 and 1830 furnish several occultations 

 of Aldebaran j when it is to be hoped that a phaenomenon, which has 

 been so little observed in Great Britain, that if it rested solely on the 

 authority of British Astronomers would be scarcely entitled to any 

 notice, will not longer furnish an object for their reproach. 



ROYAL ACADEMY OF SCIENCES AT PARIS. 



Feb. 4th, 1828. — Dr. Panquy presented an Essay on a natural 

 chemical method. — M. Moreau de Jonnes communicated some de- 

 tails relating to the late earthquakes in the Antilles M. Freycinet 



read a letter from MM. Quoy and Gaymard, dated from Tongata- 

 bou — MM. Latreille and Dumeril gave a favourable account of a 

 memoir presented by Dr. Bretonneau, On the blistering properties 

 of some insects of the Cantharides family. — M. Coquebert de Mont- 

 bret reported respecting a memoir of M. Auguste Duvau, intitled : 

 A Statistical Essay on the department of Indre and Loire, or ancient 

 Touraine. — M. Gay-Lussac announced that M. Guimet, assistant- 

 commissary in the Powder and Saltpetre Works, had succeeded in 

 manufacturing ultramarine, by combining the principles which 



chemical 



