410 Miscellaneous liUeUigencc. 



below the freezing point ot water. In this temperature, olive 

 oil alone would freeze and thicken, but being placed over water, 

 it is retained in the fluid state, in consequence of the heat 

 evolved by the water during its conversion into ice ; and it is 

 not until the whole of the water is perfectly frozen, that the 

 oil itself will freeze. — Bibliothique Universelle, xiii. 76. 



19. Formation of Succinic Acid. — Dr. John, of Berlin, states 

 that he has formed succinic acid by treating 21bs. of bread, 

 IJlb. honey, l^lb. of the fruit of the ceratonia siliqua, 2 pints 

 vinegar, 2 pints spirit, and 28 pints water, in such a way as to 

 make them undergo the acetous fermentation. The vinegar 

 formed vcas saturated with lime, and the acetate obtained by 

 evaporation. 24oz. of this salt, triturated with loz. peroxide 

 of manganese, were mixed with l6oz. of sulphuric acid, and 

 l3oz. of water, and then distilled. When no more acid came 

 over, the receiver was charged, and the fire increased, and a 

 sublimate of succinic acid came over, which condensed in the 

 neck of the retort. When purified, it weighed two drachms. 



As the process, on repetition, always gave succinic acid, 

 though the fruit of the ceratonia siliqua, on analysis, gave none, 

 Dr. John concludes that the acid was formed during the opera- 

 lions. 



20. Assay of Soda of Commerce. — M. M. Welter and Gay 

 Lussac, in a paper on the assay of soda, and the salts of soda 

 of commerce, by sulphuric acid, as is usually done, recommend 

 that the portion of soda taken should be first heated with a 

 little chlorate of potash. This is done to convert any sul- 

 phuret or sulphite of soda into sulphate ; otherwise those 

 substances are saturated by the test sulphuric acid, and 

 appear as soda in the results, though they are of no use as 

 such in the arts. The soda of commerce is frequently con- 

 taminated with those two bodies, and in every case where they 

 exist, an error will occur unless their effect be prevented as 

 above. After the action of the chlorate of potash, the test 

 acid is applied caiefuUy in the usual manner. — Ann. di Chun. 

 xiii. p. 212. 



