This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol2", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
Like the preceding, this has been omitted in the British Pharmacopoeia. Sago is prepared from the pith of the stem of an East India palm, called Sagus Rumphii, and probably other trees of the same family. The stem is cut into billets, which are split; and the pith extracted from it is agitated with water, so as to separate the starch. This being suspended in the water, subsides when the latter is poured off, and allowed to rest. The moist paste thus procured is rubbed into grains and dried. This constitutes the common sago. it is produced in great abundance in the Moluccas, and other East India islands. At Malacca and Singapore, it undergoes a refining process, and is converted into what is called in commerce pearl sago. The latter must be exposed to heat in its preparation, as it is partially soluble in cold water.
Common Sago is in grains of varying size, the largest scarcely so large as a small pea, of a whitish, grayish, or brownish-gray colour, often mixed with a grayish powder, and more or less impure. Pearl sago, which should be chosen for medical use, is in hard, round grains, of more uniform size, about as large as the head of a pin, of a lighter colour, but not perfectly white, often somewhat translucent, bright, and clean. Both varieties consist almost exclusively of starch; the common sago being quite insoluble in cold water, the pearl slightly soluble from the cause above mentioned.
Sago is employed exclusively as an article of diet, and for this purpose is very useful in low fevers, and convalescence from acute diseases. in consequence of its hardness, it requires to be boiled for some time to effect a complete solution; and, as it is given generally in a feeble condition of the digestive organs, care should be taken that the grains are completely broken up, so as to facilitate digestion. From half an ounce to an ounce may be boiled in a pint of water, according to the richness of the preparation wanted. A tablespoonful is ordinarily sufficient. The liquid should be constantly stirred during the process; and, if any hard grains remain, they should be separated by straining. Sugar and lemon-juice may be added if desired, and a little wine and nutmeg in feeble states of the system.