Page:A Practical Treatise on Brewing (4th ed.).djvu/168

152 before an opinion can be given as to their relative value. Try given weights of each sample (one-eighth of an ounce, for instance) in three ounces of water by measure, in separate vessels; bring them gradually to a boil, occasionally stirring each sample. While hot, strain the different solutions through muslin, into separate vessels. In proportion to the quantity of undissolved matter left upon each strainer, may the solubility of the different samples be ascertained; that which leaves the least residuum will form, when cold, the strongest jelly, upon which the clearing property of isinglass depends. The remaining trial to which the different samples are to be submitted, is the last and most decisive one. Equal weights of each sample (the one-fourth of an ounce, for instance) are to be cut into very small pieces, and each one-fourth of an ounce put into half a pint (imperial measure) of hard or sour beer, and the several vessels containing the different samples put into an apartment, at from 65° to 75° F., and allowed to remain there for three days, stirring each sample very well, once or twice a-day.

“At the expiration of that time, there will be an evident difference in the strength of each jelly, provided different qualities of isinglass had been submitted to the experiment; and when the thickest jelly has a small quantity of the tincture of galls applied to it, and stirred through it, it will separate the gelatine from the sample of isinglass in the