CHEMICAL SCIENCE. 219 



principle of the spice; and, by a side pipe of glass placed near the top, the 

 liquid charged with this principle is let off into a caldron or still. In this 

 is placed some substance, as common salt, or saltpetre, sugar of milk or 

 other sugar, or some other matter, as dextrine, gum, or flour, for absorbing 

 and becoming saturated with the extract. The lower portion of this still is 

 double, and steam at the temperature of 140 to 145 Fahrenheit being intro- 

 duced in the space at the bottom, the sulphuret of carbon is entirely 

 volatilized, and, passing through the worm of a condenser, is recovered, so as 

 to be used again in successive operations, while the extract is held by the 

 absorbing substance placed in the still. The length of time required for 

 continuing the process, in order to extract all the active principle, is indi- 

 cated by the color of the liquid which flows through the glass tube leading 

 from the cylinder to the still. The connection between the two is then 

 closed, and the liquor remaining in the cylinder is allowed to flow out 

 through the bottom; after which, steam is admitted to carry off the last 

 portions of sulphuret of carbon, which is collected and condensed in another 

 vessel. By this process the active principle of the spice or fruit is entirely 

 removed from its natural ligneous vehicle, and transferred entirely to sugar, 

 salt, or gum, and this retains no trace of the sulphuret of carbon; and any 

 amount of concentration can be given to the products, according to the rela- 

 tive proportions of the absorbent and of the spice employed. 



In the treating of garlic, onions, and such vegetables, the juice expressed by 

 hydraulic pressure is mixed with the sulphuret of carbon, which dissolves 

 its active principle. 



IMPROVEMENT IN SOAPS. 



Several improvements in the manufacture of soaps and cleansing prepara- 

 tions have been recently patented by Mrs. Rowland, of London. They 

 depend chiefly upon the introduction of certain chemical compounds into 

 ordinary soaps, by which their detersive properties are greatly increased. 

 The soap being dissolved in warm water, ammonia, or some ammoniacal 

 compound, is added to the solution, together with some liquid hydrocarbons, 

 or an equivalent substance, as spirits of turpentine, coal-tar, naphtha, cam- 

 phene, or some of the similar compounds derived from the distillation of 

 bituminous matters. The proportions of the mixtures are determined by 

 the nature of the soap, and the use required. On account of the volatility 

 of the substances added, much heat is avoided in mixing. It is well to add 

 some flour, dextrine, or some gelatinous or mucilaginous substance which is 

 soluble in water, as it serves as a vehicle for holding the other substances 

 in suspension or mechanical combination. Perfumes or essential oils are 

 introduced to disguise the odor of the chemical ingredients. 



The following is a more particular description of one of the processes. 

 Six pounds of soap are dissolved in two pounds of warm water. To 

 the same quantity of water are added about three and a half ounces of 

 flour, starch, dextrine, oatmeal, or some other substance; gelatine, glue, or 

 other gelatinous or mucilaginous substances may be employed, which will 

 give body to the composition, and cause the ingredients to cohere. A paste 

 is thus prepared by boiling, and is added while hot to the solution of soap, 

 and the whole is then heated and stirred till the ingredients are thoroughly 

 incorporated together. It is now taken off the fire, and the stirring is con- 

 tinued till the temperature has fallen to about 100, when about fourteen 

 ounces of spirits of turpentine, naphtha, campheue, benzole, or other such 



