1818-3 Scientific Intelligence. 153 



in a separate state, and sent to M. Stromeyer, begging him 

 to verify his conjectures. M. Stromeyer soon found that it had 

 the same properties with the metal which he had just discovered, 

 to which he gives the name of Cadmium.* 



XVIII. Experiments on Manna. By M. Bouillon-la-Grange ."f 



The principal result that M. Bouillon-la-Grange has obtained 

 is that manna consists of two substances, that seem to have 

 distinct properties, and that may be separated from each other. 

 If manna be digested with alcohol, a part of it is dissolved, an 

 amber-coloured fluid is obtained, which, by being partially eva- 

 porated and then cooled, deposits crystals in small needles. 

 This part of the manna, which is soluble in cold alcohol, appears 

 to be very analogous to sugar. What remains is a whitish-grey 

 substance, hard, and brittle, upon which cold alcohol has no 

 action ; it may, however, be dissolved in boiling alcohol, from 

 which it crystallizes by cooling. This part, when treated with 

 nitric acid, forms the malic and oxalic acids, and a quantity of 

 the mucous acid, which is precipitated. 



XIX. Experiments on Malic Acid. By MM. Bouillon-la- 



Grange and Vogel.J 



We are informed that a memoir on the subject was presented 

 to the Institute in the year 1807 ; but it appears that the expe- 

 riments were considered not sufficiently conclusive, and on this 

 account the authors were induced to reconsider them. We shall 

 not at present detail them to our readers, but we shall state the 

 propositions which they deduce from them. 



Nitric acid, however weak, forms with sugar an extractive 

 matter, which unites intimately to the acetic acid, which also 

 results from the action of nitric acid on sugar. This extractive 

 matter combines with lime, barytes, alumine, and many of the 

 metallic oxides, and forms with them compounds, which are 

 nearly or totally insoluble in water. It does not decompose the 

 earthy salts, but it decomposes many of the metallic salts, and 

 especially those with bases of lead and tin. Sometimes it is 

 found perfectly white, at other times more or less coloured, as 

 in the sap of the sycamore, and the birch, and the juice of the 

 houseleek. The juice of apples and of buckthorn contains 

 uncombined acetic acid ; and a great quantity of this extractive 

 matter, and the malic acid, which we obtain from these sub- 

 stances, is a compound of acetic acid and this extract. The 

 fluids which do not form a precipitate with the acetate of lead 

 do not contain any of the extract ; of this kind are the solutions 

 of sugar and gum, and linseed mucilage. The extract may be 

 separated by barytes, and by combining it with acetic acid, the 

 malic acid may be formed. 



* See Annals of Phil. xii. 75. 



+ Abstracted from Journ. Pharm. iii. 10. (Jan. 1817.) 



J Abstracted from Journ. Pliarm. iii. 49. (Feb. 1817.) > 



