316 Royal Society. 



gathered from our own historians. Up to the time (1831) when 

 Dr. Rosen published his edition and translation of Mohammed Ben 

 Musa, we knew nothing of the Arab writers except in fragments. 

 Dr. Rosen's contribution (which is also that of Mr. Warburton) 

 showed us the manner in which, and the writer by whom, the Indian 

 science was made Arabian. M. Woepcke lets us into the secret of 

 the progress made by the Arabs themselves ; and a comparison of 

 the writings of the introducer and of the improver will show that 

 the science had made remarkable advances. This comparison, how- 

 ever, we must leave to the interested reader, on account of the space 

 it would require. 



M. Woepcke gives the Arabic text, a French version, a running 

 paraphrase in modern language, and various additions and notes. 

 He has earned a right to the gratitude of all who take hiterest in 

 watching the progress of science, by the able manner in which he 

 has performed every part of the task of which we can judge. We 

 say this that we may not be supposed to give an opinion of the 

 translation ; this we are compelled to leave to those who know how 

 to decipher the methodical scratches and scrawls which we fully 

 believe, upon testimony, to represent Arabic words. 



Omar Alkayyami was alive in a.d. 1079 : Mohammed Ben Musa 

 lived two centuries before him. 



Photogenic Manipulation. By Robert J. Bingham. Eighth Edition. 

 Knight, Foster Lane. 



This little work contains a short account of the theory of the 

 chemical action of light, with simple directions for producing pho- 

 tographic pictures by different agents, bringing down the descriptions 

 to the most recent improvements at the time of publication. Among 

 these the production of images upon glass plates naturally assumes 

 a very prominent place, forming, as it does, in practice a marked step 

 in advance, from the extreme beauty and minuteness of detail that 

 can be attained by the employment of the transparent medium, ren- 

 dering photography still further available for scientific purposes. 



XLIX. Proceedings of Learned Societies, 



ROYAL SOCIETY. 



[Continued from p. 246.] 



May 1, 1851. — The Earl of Rosse, President, in the Chair. 



A PAPER was read, entitled " An account of two cases in which 

 an Ovule, or its remains, was discovered after death in the Fallo- 

 pian tube of the unimpregnated human female, during the period of 

 Menstruation." By H. Letheby, M.B., Lecturer on Chemistry and 

 Medical Jurisprudence in the Medical School of the London 

 Hospital. Received Feb. 20, 1851. 



At the commencement of the paper the author refers to the opi- 

 nions of Drs. Power, Lee, Paterson, Barry, Girdwood, and Wharton 



