696 PROCEEDINGS OF THE AMERICAN ACADEMY. 



Star was at first taken for a comet ; and the Astronomer Royal once 

 expected that it would have passed over the disk of the Sun at the 

 beginning of last month. But he has since told me, that it is doubted 

 whether it may not be a planet never before discovered moving at a 

 much greater distance from the Sun than Satuni. It has been for 

 some time hid by the Sun's rays. Should it appear again, Something 

 more certain will probably be determined concerning it. 



J)^ Priestly never went farther in his History of Philosophy than 

 Electricity and Optics. He has been for some time wholly employed 

 in making experim? on the different Sorts of air. In this branch of 

 Philosophy he has made several very important discoveries, an account 

 of which he has given in five Octavo Volumes, the last published this 

 Summer. One of the most important facts which he has discovered is 

 the effect of vegetation, aided by the action (not of heat but) of light 

 in purifying, preserving and restoring common air constantly injured 

 and diminished by the breathing of animals, the burning of fires, putre- 

 faction and other causes. In the day time and particularly in Sun- 

 shine, the purest kind of air is emitted by the leaves of trees and all 

 vegetables ; and this emission is more or less copious in proportion to 

 the vigour of the vegetation and the force of the Sun's light. In the 

 night and in the dark it ceases entirely. D'' Priestly is going on with 

 these experim^, and very probably another volume will be published in 

 a little time. 



If you think that my best respects and wishes will be acceptable to 

 the members of your Academy, I beg you would deliver them. No 

 one can observe with a more earnest attention than I do all that now 

 passes in America. With much gratitude and the greatest regard I 

 am, S"", your most obedient and humble Ser* 



Rich? Price, 

 Deliver my very respectful complim^ to the venerable J)' Chauncy. 

 D"" Winthrop was my correspondent. With pain I reflect that he is no 

 more in this world to promote virtue, liberty and Science. But we are 

 all following him. God grant that we may leave the world wiser and 

 better for us. 

 A copy of this letter was sent by another conveyance. 



The President called attention to the rich store of historical 

 documents possessed by the Academy, of which the letters read 

 were but a small portion. There are letters from General Wash- 

 ington acknowledging his election to the Academy ; a letter from 

 Priestly, the discoverer of oxygen ; several from Count Rumford, 

 and a host of others. 



