EXTRACTION OF OILS. 95 



dissolve most of the bromine and separate it from the water, so 

 that after standing a heavier coloured liquid will subside to the 

 bottom, consisting of the chloroform or bisulphide of carbon 

 containing the bromine in solution, whilst a much lighter coloured 

 watery fluid will rise up to the top ; the action being exactly 

 analogous to that taking place with zinc, lead, and silver, excepting 

 that the silver solution in zinc rises to the top, whilst the bromine 

 solution in chloroform sinks to the bottom. These actions are 

 precisely analogous to that occurring in Expt. 62, where iodine is 

 removed to a great extent from a watery solution by means of 

 chloroform, the chief difference being simply that iodine is a solid, 

 whilst bromine and molten silver are liquids. 



Caution. Bromine is very volatile, and its vapours are exces- 

 sively injurious to the lungs if breathed, producing much irritation 

 and coughing ; be very careful, therefore, not to inhale the fumes. 



Expt. 87. To separate two Intermixed Liquids by Evapora- 

 tion. When a liquid not easily volatilised is dissolved in another 

 that is readily volatile, separation is easily brought about by the 

 agency of heat, just as when a solid substance is dissolved in water 

 or spirit, and the solvent evaporated by applying heat (Expts. 

 37 and 38). 



Pour a few drops of olive oil into a test-tube, and then add a 

 tablespoonful of ether and shake up ; the ether will dissolve the 

 oil, and form a solution or mixture of the two liquids. Pour this 

 out into a small evaporating basin, and allow it to stand in a warm 

 place for a short time, taking care that the ether does not take 

 fire (Expt. 41) ; the ether will speedily evaporate, and leave the oil 

 unchanged. If the ethereal solution be placed in a distilling 

 apparatus furnished with a condenser (Expt. 36), the ether can be 

 condensed and recovered for use over again. 



Obtain a teaspoonful of essential oil of lemon, and add to it a 

 wine-glassful of strong alcohol; the spirit will dissolve the essential 

 oil, forming a fluid from which the alcohol may be evaporated or 

 distilled off, leaving the essential oil behind. In this case, if the 

 alcohol be recovered by condensation, it will be found that it 

 retains the odour and flavour of lemon to some extent, as this 

 essential oil is not altogether non-volatile, and consequently a little 

 distils over along with the alcohol. 



Expt. 88. To extract Oil from Seeds, &c. The principles 

 illustrated in the last experiment are applied in the arts for the 

 extraction of oily matters from seeds and various other sources, so 

 as to obtain materials useful in the manufacture of soap and 

 numerous other products. 



Crush a handful of linseed in a mortar, and place the coarsely 



