William Howes Comstock was born in London, England, and establihed his proprietary business in Morristown, New York in the late 1870s under the firm name of W. H. Comstock Co., Ltd. The chief product Comstock manufactured was Dr. Morse’s Indian Root Pills which appears to have been originated about 1835. The firm also manufactured Comstock’s Dead Shot Wormp pellets and Dr.Morse’s Compound Syrup of Yellow Dock Root which he sold at least until 1883, and which was manufactured in the 1890s by the Morse Yellow Dock Root Syrup Company of Providence, Rhode Island.
(Holcombe, Henry w., weekly Philatelic Gossip 24: 409, June 5, 1937)