i821.] New Scientific Books. 77 



mixing to it previously to the distillation l-12th part sulphuric acid 

 diluted with equal weight of water, the succinic acid will be produced 

 in about twice the quantity got in the old way. The acid is easily 

 purified by crystallization from sulphurous and sulphuric acid with 

 which it will be found contaminated. I believe the adding of sulphuric 

 acid in order to increase the production of succinic acid was first 

 noticed in a late German paper : I have forgotten by whom : it was 

 there advised that the diluted acid, after being mixed with the amber, 

 should be evaporated : this makes the process tedious, and is not 

 necessary, as several experiments have convinced me ; the distillation 

 of the mixture, without any previous evaporation, will be found more 

 advantageous. I am not aware of this circumstance being noticed in 

 any English publication ; it may, therefore, be acceptable to your 

 readers. 



II. Effects of Copper on Vegetation. 



Some time since I accidentally spilt some solution and oxide of 

 copper near the root of a young poplar tree. In a short time, the tree 

 began to droop, the leaves on the lower branches dying first, and 

 erentually those on the upper ones. On cutting a branch from the 

 tree, I observed that the knife was covered with copper to the whole 

 breadth of the branch, showing that the copper had been absorbed, 

 and had undoubtedly proved fatal to the life of the tree. I am not 

 aware whether this circumstance has been before remarked. — Ed. 



III. Ignition occasioned by Sulphuric Acid and Barytes. 



Mr. Barry informs me that when concentrated sulphuric acid is 

 poured upon caustic barytes, ignition ensues. This circumstance 

 was first noticed on using the acid to determine whether the nitric acid 

 had been perfectly expelled from the nitrate in preparing the caustic 

 barytes. It has been already noticed that light is evolved when sul- 

 phuric acid is poured upon lime or magnesia, but I do not know that 

 ignition has been observed similar to that which I have now described. 

 —Ed. 



Article XV. 

 NEW SCIENTIFIC BOOKS 



PREPARING FOR PUBLICATION. 



Dr. Adam Dods will shortly publish the Physician's Guide, being a 

 popular Dissertation on Fevers, Inflammations, and all Diseases con- 

 nected with them. 



Mr. S. F. Gray has in the press, in two octavo volumes, a Natural 

 Arrangement of British Plants, preceded by an Introduction to 

 Botany. 



JUST PUBLISHED. 



A Syndesmological Chart, or a Table of the Ligaments of the 

 Human Skeleton, by J. Dickinson, MD. Is. 



The History of the Plague, as it has lately appeared in the Islands 

 of Malta, Gozo, Corfu, Cephalonia, &c. detailing important Facts 

 illustrative of the specific Contagion of that Disease, with Particulars 

 of the Means adopted for its Eradication. By J. D. Tully, Esq. 8vo. 

 10*. 6d. J J> i 



