This section is from the book "Meals Medicinal", by W. T. Fernie. Also available from Amazon: Meals Medicinal: With "Herbal Simples" Curative Foods From the Cook in Place of Drugs From the Chemist.
This is a starch obtained from the roots of several species of Maranta, chiefly the variety "Arundinacea" (West Indian). Brazilian Arrowroot (tapioca meal) is got from the roots of the Manihot utilissima, after first withdrawing their poisonous juice. English Arrowroot is made from the potato; and Portland Arrowroot from the corms of the Arum maculatum ("lords and ladies"). When dry, Arrowroot starch (eighty per cent) is put for packing into new barrels lined with paper, else it would become contaminated by surrounding flavours.
The absorption of Arrowroot, if simply prepared with water as a food, is altogether complete. Hence this starch is specially valuable in the treatment of irritative, or continued diarrhoea. But it does not furnish any proteid nourishment for growth, or muscular development. Furthermore, for contributing bodily warmth arrowroot (unless combined with milk and sugar) is of but feeble effect. Dr. Hutchison tells us that a cupful of water-arrowroot contains only about thirty grains of starch. It would afford to the body less than a two hundredth part in fuel value of what even an invalid requires daily. The cheap kinds of arrowroot are quite as nourishing as those which are expensive.