Intelligence and Miscellaneous Articles. l 233 



It is proper to observe, that in trying an essential oil it is right 

 to employ but a very small portion at first, and to add successive por- 

 tions gradually ; otherwise, if the proportion of alcohol be very small, 

 it may be absorbed by the chloride without sensibly altering it, and 

 even without showing its presence. It is easy when the operation 

 is over to determine the proportions of a mixture of alcohol and 

 essential oil, by comparing its weight or volume with that of the 

 pure oil which floats upon the alcoholic solution of the chloride. 



The same process, the author states, may be employed for deter- 

 mining the quantity of alcohol which aether contains ; but the tube 

 should be longer, and not too perfectly closed. — Journal de Fharm., 

 Juin, 1840. 



(ECONOMICAL PREPARATION OF ACETONE. 



M. Zeise of Copenhagen observes, that when a considerable quan- 

 tity of acetone is required, the methods usually employed are too ex- 

 pensive, and he recommends the following process : mix thorough- 

 ly one part of well-powdered quicklime with two parts of powdered 

 crystals of acetate of lead. Soon after the mixture is made, the 

 lime usually begins to heat violently ; but as no smell of acetone is 

 perceptible, there is no sensible loss of it ; it is -better to put the 

 mixture into the distillatory apparatus before this heating occurs, 

 because afterwards the mass is so great that the introduction is more 

 difficult. M. Zeise states that he has not found it advantageous to 

 attempt getting rid of this circumstance by employing slacked lime ; 

 for in this case dried acetate must be used to prevent the product from 

 containing too much water, and the drying of the acetate is more 

 troublesome than powdering the lime. 



The iron bottles in which mercury is imported, suit for this ope- 

 ration extremely well ; four pounds of the acetate may be operated 

 upon at once ; the bottle is placed almost horizontally in the fur- 

 nace, but so that the opening is rather raised ; to this a slightly 

 curved short tube is adapted, and luted with a mixture of clay, 

 chalk and salt, and this enters into a glass tube sufficiently large, 

 properly curved and surrounded with a tin-plate pipe, in which an 

 ascending current of water is kept up ; and lastly, to this a receiver 

 surrounded with ice is attached. The heat is slowly raised, and it 

 is only towards the end of the operation that it is increased to red- 

 ness. 



The product is a mixture of acetone, a small quantity of water, 

 two oily substances, which are less volatile than acetone, one of 

 which is probably the dumasine of Kane. 



From this product pure acetone is obtained by dissolving chloride 

 of calcium in it, distilling the solution in a water-bath, until at 212° 

 nothing more passes over ; the product is to be again treated with 

 chloride of calcium, and three-fourths being distilled will be found 

 to be pure acetone. 



On adding water to the residue, the oily bodies are separated 

 from the acetone, which dissolves in the water and is separated from 

 it by chloride of calcium. 



