JfEW OLEAGINOUS COMPOt^ND* j^9 



precipitate: this precipitate was afterwards thrown on 

 a filter, and washed with a weak solution of alcohol 

 in water. After passing through the filter, and remain- 

 ing some time, crystals of the acid were formed. , When to 

 another portion of the same solution (benzoate of potash) 

 heated, sulphuric acid was added, a very peculiar change 

 ensued, viz. the benzoic acid was immediately precipitated 

 in beautiful flaky crystals, and left the sulphate of potash 

 in solution. 



Exper, 2, — In trying how much benzoic acid and cam- J?.r;>.2.— None 

 phor was necessary to the formation of this compound, I "^^^^ con^- 

 found, that from the following proportions none of the ed when too 



oleaginous sabstance was produced. much of the 



'^ ^ menstruum 19 



Benzoic acid gr. xx, camphor gr. xx, alcohol an ounce, present. 



water the same. It will appear from this experiment, that 

 the combination is only produced, when the substances 

 which are necessary to its formation are in a certain ratio 

 with respect to the quantity and purity of the alcohol em- 

 ployed ; for it seems, that when they are so much diluted 

 with alcohol and water, the affinity of the benzoic acid for 

 the camphor is counteracted by the superior attraction of the 

 alcohol for this body; and thus the benzoic acid and cam- 

 phor are preserved in solution, without being able to exert 

 their mutual affinities to produce the new combination. 



In repeating these experiments in larger proportions, I Crystals 

 observed some crystals, varying from half an inch to an °^"^^ ' 

 inch in length, were formed (on standing for several hours) 

 in the fluid above the oleaginous compound, and which I 

 thought, from their magnitude, were composed of benzoic 

 acid and camphor. It may also be proper to remark, that 

 crystals are formed in the oleaginous substance, but much 

 inferior in their magnitude to those which are found in tho 

 supernatant stratum. 



Examination and properties of the crystals. — They were Their propo^ 

 of an irregular, oblong, and flat shape; acid, partially ^^'^*" 

 soluble in cold water, but perfectly so at the temperature 

 of 212**. When dissolved in a solution of the subcarbonat« 

 of potash, a quantity of carbonic acid gas was evolved ; but 

 no camphor was separated. When dissolved in alcohol^ " 

 thej gave to it acid properties ; and on the addition of wa- 



