414 Coniributions to the [June, 



lu consequence of tlie great solubility of these crystals, it is 

 difficult to determine their specific gravity ; but it does not seem to 

 differ much from that of muriate of manganese. 



The solution of these crystals is decomposed by the alkaline oxa- 

 lates and phospliates. 



ACTION OF BliNZOIC ACID. 



a. O/i the Metal. 



Benzoic acid acts very slowly upon metallic manganese. If they 

 be digested together in water for some hours, the water is docom - 

 posed, and the inetal is converted iato a light green oxide, which 

 gradually dissolves in the acid. The soiution possesses the same 

 properties as the following. 



l\ On the green Oxide mid white Carbonate. 



Both are very slowly dissolved in benzoic acid by the assistance of 

 heat, the last with a very feeble eftervescence. The solutions are 

 colourless and readily crystallize. 



Properties of the Crystals. 



Benzoate of tnanganese by slow evaporation crystallizes in long 

 thin prisms ; but when we evaporate rapidly we usually obtain irre 

 gular plates. 



The crystals are colourless, transparent, not altered by exposure 

 to the air. Tiie taste is at first sweet and somewhat astringent, 

 but it becomes at last bitterish. 



At the temperature of 66° they dissolve in 20 times their weight 

 of water. They are much more soluble in boiling water, and the 

 solution crystallizes as it cools. They are soluble likewise in alco- 

 hol. The solution is decomposed by ttie alkaline prussiates, car- 

 bonates, phosphates, and tungstatcs. 



100 grains of this salt distilled in a retort till they were decom- 

 posed gave only some drops of water, but furnished a considerable 

 auantity of oil. This oil had the colour, consistence, and agree- 

 able taste of oil of cinnamon, which at first was mixed with the 

 taste of prussic acid, though none of that acid could be detected 

 by the most careful examination. The residuum in the retort after 

 being fully charred, was dissolved in muriatic acid, and precipitated 

 by carbonate of potash. The oxide obtained weiglied 24 parts. 

 Hence 100 grains of benzoate of manganese consist of 



Green oxide 24 



Acid and water 1G 



100 



ACIION OF SUCCINIC ACID. 



a. On the Metal. 

 Manganese .dissolves very rapidly in succinic acid. During tlie 



