SODIUM ACETATE IN WARMING BOTTLES
Recently the laboratory’s attention was called to the “ThermoR Waterless Hot Bottle,” manufactured by the Royal Thermophor Sales Co., New York. The following claims appear in one of the advertising pamphlets:
“There is moist heat.” “Rubber hot-water (? ? ?) naturally give a moist heat.” It (ThermoR) gives a dry heat.
“The ‘THERMOR’ Bottle is not a hot-water bottle—it acts on a principle that is entirely different and new.”
“... gives you first, last and all the time a fixed degree of dry usable heat—a heat that holds steadily at 125 degrees for fully twelve hours—you will easily see why it is that ‘THERMOR’ relieves and cures where hot-water bottles fail.”
The bottle was nickel plated, 83⁄8 inches in diameter and 11⁄2 inches thick, and in appearance resembled an exaggerated closed Ingersoll watch.
The bottle is not flexible and weighs 31⁄2 pounds. The contents consisted essentially of sodium acetate. This salt melts when heated. When it cools the temperature inside the bottle is relatively constant, as it will remain at the “freezing point” until all of the sodium acetate has solidified. The duration of the time that it remains warm when well wrapped is simply in inverse proportion to the conductivity of the surrounding environment. When two ordinary towels were carefully arranged about it, the air between the bottle and the wrappings was maintained at a temperature of 40–50 C. (104–122 F.) for a period of eight hours.
The company’s implication that the heat given out by the Thermor bottle differs from that given out by an ordinary hot-water bottle is an absurdity. The use of sodium acetate in the preparation of warming bottles has been in practice many years, and is not “a principle that is entirely different and new.” Furthermore, the therapeutic claims are extravagant.—(From Reports A. M. A. Chemical Laboratory, 1916, p. 105.)