18G5.] Chemistry. 281 



and prolific source of the body has been discovered in a substance 

 which seems to be hardly available as an article of diet. The negroes 

 of Soudan and tropical West Africa hold in high esteem the seeds of 

 cola acuminata, known as the Guru-Nut of Soudan, or Kola-Nut of 

 West Africa. In these Drs. J. Daniel! and Attfield have discovered that 

 theine exists in almost as large a proportion as in tea. As, however, 

 the taste of the nuts seems to be unpleasant to European palates, and 

 no mode of preparation is yet known to make it agreeable, they do not 

 seem to be suited for an article of diet. We content ourselves, there- 

 fore, with pointing them out as a new source of theine. 



Proceedings op the Chemical Society. 



Since the publication of our last notice, the Chemical Society has 

 been engaged for the greater part of two evenings in discussing Che- 

 mical Nomenclature and Notation. The subject was introduced by 

 Professor Williamson, who, being engaged on a new elementary work, 

 is ambitious of introducing a more precise and satisfactory system than 

 that which is at present current. It would be impossible to convey 

 to our readers, in the short space we can devote to the subject, an 

 adequate idea of the Professor's views — hardly elaborated with suffi- 

 cient distinctness, in the communication read — and we therefore wait 

 the publication of the work in which we shall find the system he pro- 

 poses applied. In the meantime, it was eminently unsatisfactory to 

 find from the discussion, in which all our leading teachers joined, that 

 chemists are by no means agreed upon the fundamental principles which 

 must guide us in the adoption of a perfect system of nomenclature. 

 Sir B. Brodie, indeed, seems to be of opinion that chemistry has 

 reached a stage in which it will be found convenient to abolish the 

 use of names altogether, and to describe things by formula? alone. 



Some laboratory memoranda communicated by Mr. E. Warington, 

 jun., contained practical information of much interest. The colour- 

 changes produced by the reaction of ferricyanide of potassium on ferric 

 salts are variously described in Manuals of Chemistry, some asserting 

 that dark or reddish brown fluid is produced, while others state that 

 the liquid is greenish or dark-green. The author showed that these 

 different appearances are produced by varying the proportions of the 

 reacting compounds. Thus, the dark-brown liquid is produced when 

 the ferricyanide is in excess of the ferric salt ; and when the propor- 

 tions are reversed the green colour results. With regard to the ques- 

 tion cf a precipitate, it was shown that when sufficiently acid the 

 liquid remained clear ; but with basic ferric salts a pale-brown preci- 

 pitate is thrown down by ferricyanide of potassium. 



Another memorandum on the solubility of magnesia in alkaline 

 salts, showed that magnesia is to some extent soluble in salts of potas- 

 sium and sodium, as well as of ammonium, though to a far smaller 

 degree. 



The most interesting meeting of the season, has been on the 

 occasion of a discourse by Dr. Hofmann, on Lecture Experiments. 

 There are several unquestioned facts in chemistry which must in 

 "feneral be taken for granted, since their experimental demonstration 



