a. [ad. med.L. subtractīvus, f. subtract-; see SUBTRACT v. and -IVE. Cf. Pg. subtractivo.] Involving or denoting subtraction, deduction or diminution; (of a mathematical quantity) that is to be subtracted, negative, having the minus sign.
1690. Leybourn, Curs. Math., 808. We have therefore now three Prosthaphæreses of the Moon…. Which since they are all of the same sort, to wit, each of them subtractive [etc.].
1699. Phil. Trans., XXI. 352. Subtractive Ratio is that whose Terms are dispos’d to Subtraction, that is, to Division.
1812. Woodhouse, Astron., xiv. (1821), 381. The resulting numerical values … if additive of the north polar distance, are subtractive of the zenith distance.
1813. Monthly Mag., XXXVI. 307. However—Yet—Notwithstanding—Nevertheless. These may be called subtractive conjunctions: they all concede something, and deduct something else.
1824. R. Jackson, View Formation, etc. Armies, 505. Besides measured diet,… there are other means … diminishing the volume of the fluids…. These are subtractive, viz. blood letting and purging.
1829. Bentham, Justice & Cod. Petit., Prelim. Explan. p. vi. To employ either draft, with … amendments, whether additive, subtractive, or substitutive.
1890. H. B. Fine, Number-Syst. Algebra, 102. In reducing equations … subtractive terms in either member are rendered additive by transposition to the other member.
b. Cryst. (See quot. 1805–17.)
1805–17. R. Jameson, Char. Min. (ed. 3), 147. Tetrahedral and prismatic molecules are always arranged in such a manner in the interior of primitive and secondary crystals, that, taking them in groups of 2, 4, 6, 8 they compose parallelopipeds…. These parallelopipeds are by Hauy named subtractive molecules.
1823. Brooke, Crystallogr., 66. A more simple theory of decrement … may be substituted for that which has been established upon the assumption of the irregular tetrahedron as the integrant molecule, and the obtuse rhomboid as the subtractive molecule.
