312 Scientific Intelligence, c\c. 



4. Mr. Davidson, a gentleman of fortune and accomplishments, 

 well known in London, by his interesting descriptions of Jerusalem 

 and Thebes, at the Royal Institution, of which we gave reports, 

 (Records, i. 322, ii. 7*2,) has started for Africa, with the intention 

 of penetrating to Timbuctoo, examining the range of Atlas in his 

 way, and proceeding by Tafalet. He has taken with him an ex- 

 traordinary man, who was born at Timbuctoo, and whose father was 

 governor of Gana — having been carried as a slave to Jamaica, where 

 he was found at the age of 50, or more, by Dr. Madden. This 

 gentleman was struck with him, in consequence of his astonishing 

 acquirements, as he speaks several African languages with great 

 accuracy, and writes Arabic beautifully. Dr. Madden wrote an 

 account of him to this country, and Mr. Davidson requested, that he 

 should be sent over at his expense. While in London, he was intro- 

 duced to the Duke of Sussex, who promised him, that if he should 

 prove faithful to Mr. Davidson, he should, on his return to England, 

 be provided for in one of the Royal palaces for life. He left this 

 country, deeply impressed with the kindness he had received, and 

 the last letters from Mr. Davidson, speak of him in the most flatter- 

 ing strains. 



5. The last accounts from the Euphrates expedition, which was 

 then at Birr, living in, what with little regard to classical taste, has 

 been called Fort William, were by no means favourable, the greater 

 part of the members of the expedition being in a bad state of health. 

 The enthusiasm, however, of the commander continued unabated. 



IV. — On Chemical Symbols. 

 To the Editor of the Records of General Science. 

 Sir, — It is with regret that I see so little attention paid to the in- 

 vitation which you gave to the chemical world to discuss the subject 

 of symbols in the pages of your Journal. If you consider the follow- 

 ing observations of any importance, perhaps you will give them a 

 place in the Records. 



Though the importance of symbols appears on all hands to be 

 admitted, yet very few, and these very imperfect, attempts appear to 

 have been made to supply a set, which will be applicable to all branches 

 of chemistry, and which shall be free from objections or defects. 



The idea of symbols appears to have originated with Dalton, 

 and to have been employed by him in the elucidation of his 

 immortal discovery, the Atomic Theory. But the variously 

 marked circles, which he employed, though sufficient to illustrate 

 the nature of atomic compounds, are, nevertheless, so evidently 

 inadequate to answer the end for which symbolic representation is 

 required, that no one, I believe, has ever thought of employing 

 them for that purpose. The next step in the improvement of symbols 

 appears to have been by Thomson in his system, as has indeed been 

 observed by yourself, by substituting the initial letters of the sub- 

 stance, for the circular marks of Dalton, and expressing the com- 

 pound by connecting together the symbols of the substances of which 

 it is composed. This suggestion may be considered as the foundation 



