17 



A Suit of Asiatic Chain Armour was exhibited. It was 

 presented to the Institution by Mr. Owen Jones, of Seaforth. 

 Dr. Brett communicated the results of an analysis he 

 had made of some crystals, of an ammoniacal salt, found in 

 guano brought from Patagonia. They consisted mainly of 

 bicarbonates. He conceived that this salt was derived from 

 the oxalate of ammonia, through certain atmospheric 

 changes, as the absorption of oxygen, water, and carbonic 

 acid. Dr. Brett also explained the formation of Oxalate of 

 Ammonia (a salt found in considerable quantities in guano) 

 from ( the decomposition of the ammonia, and suggested 

 that bicarbonate of ammonia would be found to be an 

 important fertilizer, not only in consequence of the ammo- 

 nia present, but of the carbonic acid which it gives off, at 

 no very elevated temperature, and in a manner highly 

 favourable for its absorption by plants. 



THE PAPER FOB. THE EVENING WAS, 



" PHYSIOLOGICAL AND CHEMICAL OBSERVATIONS ON THE 

 GROWTH AND AGE OF TREES."—.% Dr. Dickinson and Dr. Brbtt. 



FIFTH MEETING. 



ROYAL INSTITUTION, December 15th, 1845. 

 The PRESIDENT in the Chair. 



Mr. Johnson exhibited a specimen of chrystallized 

 Copper. 



The President read a letter from Mr. Povey, dated 4th 

 March, 1660. It was sent from Gresham College, at the 

 instigation of the Royal Society, and consisted of full 

 inquiries concerning the natural products of "Virginia. 



Dr. Trench gave some details of the cultivation of the 

 Silkworm in Jamaica ; and stated that the leaf of the 

 bread-nut tree was found to be better food for it than that 

 of the white mulberry. 



Mr. Johnson exhibited a species of the Crested 

 Cockatoo. 



The President read some very interesting original 



D 



