MEDICINAL USES OF HOPS. 23 



L'.ixir of Lupuline. Triturate 2 ounces of fluid extract of lupuline with 

 two ounces of carbonate of magnesia, add 14 fluid ounces of simple elixir, 

 transfer to a bottle, agitate occasionally for several hours, and filter. 



Extract of Hops. In 1872, Professor C. A. Seeley,of New 

 York, patented in the United States and England an im- 

 proved process for extracting the useful substances of hops, 

 and for manufacturing a pure and concentrated extract of 

 hops. The invention is based on the discovery that the 

 ordinary petroleum oils are rapid and complete solvents of 

 the essential oils and of the bitter matter of hops. At the 

 same time they have no solvent action on the other con- 

 stituents of the plant, which in practical operations are either 

 useless or hurtful. The improved process consists in steeping 

 the hops in petroleum oil, and then by heat, stirring, diges- 

 tion, and percolation, promoting the solvent action of the 

 oil. When the extractable matter of the hops has been thus 

 dissolved, the solution of hop extract in oil is separated by 

 filtration from the refuse matter, and the solvent is volatilized 

 or distilled off by heat ; the extract thus being obtained free 

 from the solvent and other foreign matter. 



The kinds of petroleum oil proper for this purpose are 

 naphtha and gasoline, which are the lighter and more volatile 

 parts of crude Pennsylvania petroleum. Although any petro- 

 leum oil which has a boiling point below 212 Fahr. may be 

 used, a gasoline which boils at about 100 Fahr. is preferable, 

 because at that temperature the essential oil of hops will not 

 escape from the extract solution when distilling the solvent. 



The apparatus employed in manufacturing the solution 

 and distilling the solvent is such as is suitable and well 

 known for use where bisulphide of carbon, ether, hydro- 



