Heath, Laban. HEATH’S GREATLY IMPROVED AND ENLARGED INFALLIBLE GOVERNMENT COUNTERFEIT DETECTOR, AT SIGHT.… Boston and Washington: Heath, 1866 and 1867 [correct patent date of July 2, 1867, stated on cover]. Innes and Niles, Stereotypers and Printers. Second edition. Small 4to, original maroon cloth, front cover lettered in gilt. 39, (5) pages; 4 illustrations of Heath magnifying glasses in the text; finely engraved frontispiece; facsimile Treasury Department letter; Heath bank note facsimile plate with plate number punched, as issued; 12 finely engraved plates of bank notes and design elements, with original tissue guards, interspersed in the text, Plate 12 comprising an impression of a $100 National Currency counterfeit note printed in green and black ink; Plate 5 printed in green ink. Binding, mostly front cover, with minor discoloration; near fine. Newman 2-BH-3(b). The variations in the 2-BH-3 Heath counterfeit detectors are minor; I described four of them in my catalogue of the Eric P. Newman Library (sold by Heritage in 2018). The Heath bank note facsimile plates used in this printing are encountered both with and without a printed plate number (which, when it is encountered, is hole-punched); the front cover lettering sometimes includes the patent date, but not always, and when it does it may or may not be correct; the Treasury letter may or may not be present; and Plate 12 may or may not have a printed label about Charles Ulrich affixed below it. It is possible that further differences remain to be discovered—indeed, this copy is slightly different from the 2-BH-3(b) in the Newman Library, which had had different cover lettering but was internally identical to this example. This particular subvariety is made most distinct by the presence of the correct patent date on the front cover. The relative scarcity of these varieties has yet to be established. Ex Kolbe & Fanning Sale 128, lot 1039.