214 AXXL T AL OF SCIENTIFIC DISCOVERY. 



The crude oil answers well for paints and varnishes, and makes ex- 

 cellent soap. The refined is considered little inferior to olive oil. 



Fatty Acids for Soap and Candles. M. Mouries, in a memoir to 

 the French Academy, suggests a cheap and easy method of sepa- 

 rating stcaric and oleic acids and glycerine. In the ordinary state 



r^ *> 



tallow is saponified with difficulty. By melting the tallow in water, 

 containing a little soap in solution, the tallow assumes a globular 

 state, and is then readily attacked by a small quantity of alkali. 

 When the mixture is raised to GO C, the alkali and glycerine quickly 

 separate. The fatty acids arc separated by placing the soap in water 

 acidulated with sulphuric acid. The stearic acid will then crystallize, 

 and the oleic acid can be obtained, almost colorless, with the sulphate 

 of soda, and can then be made into soap. M Chevreul commended 

 this process, before the Academy, as ingenious and simple. 



Preparation of Essential Oils. Mr. T. 13. Groves of London sug- 

 gests an exceedingly ingenious method for the separation of essential 

 oils from watery solutions in which they exist in small quantities, such 

 solutions being frequently produced by the distillation of aromatic 

 herbs, etc. A proportion of olive oil is added to the aromatic solu- 

 tion ; this is then formed into a soapy emulsion by the addition of 

 potash. When this emulsion is destroyed by the addition of an acid, 

 the olive oil rises to the surface, bringing with it all the aromatic oil, 

 which may then be readily dissolved out of the fatty oil by agitation 

 with rectified spirit. 



The Volatile Constituents of Petroleum. Mr. E. Ronalds in are- 

 cent paper before the Royal Society, Edinburgh, stated, that the 

 gases dissolved in Pennsylvania petroleum, and which give it such a 

 high degree of inflammability, were composed of the lower members 

 of the marsh gas series. Gases taken from the surface of the liquid, 

 as imported in casks from America, were shown by eudiometrical ana- 

 lyses to contain a mixture of nearly equal proportions of the hydrides 

 of ethyl and propyl. The same compounds were found in the gases 

 evolved on warming the volatile liquid : after these succeeded the hy- 

 drides of propyl and butyl, and finally there was evolved nearly pure 

 hydride of butyl. This liquid has a spec. gr. of 0*600 at the melting 

 point of ice, and is consequently the lightest liquid known. Its va- 

 por density is '2' 11. It is colorless, and has a sweet, agreeable odor. 

 Alcohol at 98 p. c. dissolves between 11 and 12 times its volume of 

 this vapor. 



J/ujiK'J'aHion of Protoxyd of Nitrogen. One of the most interest- 

 ing" objects at a recent soiree at the Paris Observatory consisted in the 

 exhibition of the liquefaction of laughing gas, the protoxyd of nitro- 

 gen, by M. Bianchi. This took place at zero, Centigrade, under a pres- 

 sure of thirty atmospheres, the fluid issuing in a small jet. from a 

 strong metallic reservoir. Keceived in a glass tube, it retained its 

 liquid condition by reason of the depression of temperature produced 

 by evaporation, so that mercury, being introduced, solidified and could 

 be hammered like lead. Simultaneously, a body in the state of igni- 

 tion, plunged into the atmosphere of the liquid, in which the mercury 

 froze, burnt with a brilliant light. On pouring the protoxyd into a 

 small platinum capsule heated to redness, the liquid was found to re- 

 tain all its properties while assuming the spheroidal state, and was still 



