1818.J their Combinations with Alkalies. 281 



odour was more powerful ; it was perfectly fluid at 68° ; at this 

 temperature its specific gravity was "924 instead of *917, which, 

 was the specific gravity of the oil in its natural state. 



One hundred parts of alcohol, of the specific gravity of '820, 

 dissolved 1494 parts of the oil at the temperature of the atmo- 

 sphere ; at 127-5° the solution began to be turbid ; it was slightly 

 acid by the test of litmus, and the colour of the fluid was 

 converted into a blue by the addition of water, as if it had con- 

 tained an acid fat. In order to del ermine whether this was 

 actually the case, or whether the acidity depended upon the 

 development of the acid which had been detected in the aqueous 

 fluid that was obtained from the soap of the oil, when it was 

 decomposed by the tartaric acid, as mentioned above, the oil 

 was treated with magnesia, because this base has the property 

 of completely neutralizing acids, and does not acidify fatty bodies 

 in the same manner with potash and soda. 



About six parts of oil which were slightly acid were mixed 

 with two parts of caustic magnesia, and about 100 parts of 

 water ; when subjected to a gentle heat they formed a kind of 

 emulsion. More water was added, and the heat was increased; 

 the fluid was filtered while it was still warm, and was found to be 

 without acidity. Being evaporated to dryness, a residuum was 

 obtained of a red colour, which had the odour of the acid refer- 

 red to above, and weighed 0*02. The residuum was composed 

 of this acid united to magnesia, and of the orange-coloured 

 matter. The compound of oil and magnesia was put upon a 

 moistened filter, in order to remove from it any water which it 

 might contain ; it was then exposed to a gentle heat, and 

 treated with alcohol of the specific gravity of *791. The solu- 

 tion was concentrated and mixed with water; an oil was obtained 

 of an orange yellow colour, which at the temperature of 59° 

 concreted into a species of butter ; it had lost some of its odour, 

 it had no action upon paper stained with litmus, nor did its alco- 

 holic solution affect the tincture of litmus. About 4*5 gr. of this 

 oil were burned, and left only a trace of residuum, which was too 

 small to be appreciated by a very delicate balance. It follows 

 from this experiment that the acidity of the oil of the Delphinus 

 depends upon the acid mentioned above, and not upon a proper 

 acidification of the oil itself. 



hive parts of oil which was not acid were saponified by three 

 parts of potash dissolved in water; the substances were kept 

 bested for 15 hours ; the saponaceous mass resulting from the 

 operation was then dissolved in water, but the solution was not 

 perfectly limpid. The soap was decomposed by tartaric acid, 

 and tin aqueous fluid was separated from the fatty matter : these 

 two Bubstances were then separately examined." The aqueous 

 fluid was distilled ; when it was concentrated into the state oi'a 

 ■vrup, water was added, and the distillation was continued, until 

 all the volatile parts which might yet remain in the residuum were 

 driven off"; the fluid, after being duly evaporated, was then 



