Royal Society. 67 



but exhibits him as a man well calculated for the profession he 

 has chosen, since no requisite is more essential in the formation 

 of a school-master, than the art of conveying instruction. The 

 work is illustrated by 100 diagrams neatly cut on wood. In a 

 word, we are of opinion, that this book will be found to be what 

 Mr. Dowling suggests in hisPrefece, "an acquisition to everyClass 

 of Mathematical Students, and to Officers of the Army? Navy, 

 and Honourable Com[)any's service." 



Mr. Robert MacWilliam, architect, has In tlie press " An 

 Essay on the Origin and Operation of the Dry- Rot; in which 

 the source of the disease is investigated, with a view to establish 

 the modes of prevention and cure on rational principles, it will 

 make a quarto volume, illustrated with plates ; and to it will be 

 annexed suggestions on the cultivation of forest trees, with abs- 

 tracts of the forest laws from the earliest times. 



Dr. Kitchener has just published a Third Edition of his useful 

 little work entitled " Practical Observations on Telescopes, Opera 

 Glasses, and Spectacles." We gave a short notice of this work 

 on its first appearance in our Number for December 1814. 



XII. Proceedings of Learned Societies, 



ROYAL SOCIETY. 



wN the 20th of November the Croonian Lecture was read by 

 Sir Everard Home, describing the changes which blood under- 

 goes in the act of coagulation. It resulted from some microscopic 

 experiments, in which Sir Everard was assisted by Mr. Bauer, 

 that 2,560,000 globules of human blood, when enveloped in their 

 colouring matter (which he conceives to be something superadded 

 to their proper substance) would be required to cover a square 

 inch. He supposes that the globules possess a regularly organized 

 structure : they were observed to range themselves in lines, which 

 when examined and compared with the muscular fibre, under 

 high magnifying powers, led to the conclusion that these particles 

 are the constituents of the fibre. The blood in coagulating as- 

 sumes a tubular texture, an effect produced by the extrication of 

 gas during the coagulation. 



Nov. 27. A paper by Mr. Seppings on the strength given to 

 ships by diagonal braces was read, and claiming for the author 

 the originality of the invention. 



Dec. 1. The election of Office-bearers took place. — (See our 

 Number for December.) 



Dec. 1 1. A Memoir by Captain Burney was read. On the Geo- 

 graphy 



