• Proceedings of Learned Societies. 63 



the ants had gained possession he found that they might be expelled 

 by the free use of the arsenical soap employed in preserving 

 animal skins. This soap, which is a compound of common soap, 

 carbonate of potash, and white arsenic, is made into a lather with 

 water, and brushed over the articles which it is wished to preserve. 

 The great objection to such a proceeding is obviously the danger to 

 the health of the inhabitants from the dissemination of the arsenic 

 into the atmosphere. 



Mr. Robinson stated that the ravages of the white ants on the 

 sleepers and other wood work of the East Indian railways had been 

 entirely prevented by the use of creosote, but the exceedingly objec- 

 tionable odour of this remedy would prevent its being used in a 

 dwelling-h ouse. 



PHARMACEUTICAL SOCIETY.— Jaw. 6. 



Preparation of Essential Oils. — Mr. T. B. Groves suggested 

 an exceedingly ingenious method for the separation of essential oils 

 from watery solutions in which they exist in small quantities, such 

 solutions being frequently produced by the distillation of aromatic 

 herbs, etc. 



A proportion of olive oil is added to the aromatic solution ; 

 this is then formed into a soapy emulsion by the addition of potash. 

 When this emulsion is destroyed by the addition of an acid, 

 the olive oil rises to the surface, bringing with it all the 

 aromatic oil, which may then be readily dissolved out of the fatty 

 oil by agitation with rectified spirit. 



LONDON INSTITUTION".— Jim. 20. 



Sources ov the Nile.— Dr. Beke delivered a lecture on the 

 Sources of the Nile, in which he demurred altogether to the con- 

 clusions of Captains Grant and Speke, as to the origin of that river 

 in the Lake Victoria Nyanza. Dr. Beke maintains that the Nile 

 merely flows through the Nyanza Lake, its true origin being in the 

 Mountains of the Moon, which run from north to south parallel to 

 the east coast. 



The mountains laid down by Captain Speke at the northern ex- 

 tremity of the Lake Tanganyika, are stated by Dr. Beke to be 

 entirely imaginary. 



Dr. Beke stated that Captains Grant and Speke had left a most 

 important part of the river unexplored, namely, a large bend that 

 extended for at least 200 miles, and that in this portion there was a 

 fall of 1000 feet, which had not yet been examined or explained. 

 The true source of the Nile Dr. Beke maintained to be the range 

 of snow mountains on the eastern side of the Nyanza Lake, a district 

 unexplored by Captains Grant and Speke's expedition. The maps 

 exhibited by Dr. Beke showed that the recent explorations proved 

 the correctness of the theories he had submitted to the Geogra- 

 phical Society in 1849, and he proposed to undertake again in 

 person the command of another expedition, which would be 



