Mix 1000 g of Senna, in coarse powder, with a sufficient quantity (600 mL to 800 mL) of menstruum consisting of a mixture of 1 volume of alcohol and 2 volumes of water to make it evenly and distinctly damp. After 15 minutes, pack the mixture firmly into a suitable percolator, and cover the drug with additional menstruum. Macerate for 24 hours, then percolate at a moderate rate, adding fresh menstruum, until the drug is practically exhausted of its active principles. Reserve the first 800 mL of percolate, and use it to dissolve the residue from the additional percolate that has been concentrated to a soft extract at a temperature not to exceed 60
. Add water and alcohol to make the product measure 1000 mL, and mix.