GIBBS, J. Willard. "Quaternions and Vector Analysis" in Nature, 17 August 1893, pp 364-367 in the issue of pp 361-384. Weekly issue removed from larger bound volume. A tight, 3,000-word letter to the Editor. Nice copy. $175 --This is one of the war letters to Nature in which the battle for quaternions/vector analysis was played out1, and in this one Gibbs is not pleased with P.G. Tait.
"In a paper by Prof. C. G. Knott on “Recent Innovations in Vector Theory,” of which an abstract has been given in NATURE (vol. xlvii. pp. 590–593; see also a minor abstract on p. 287), the doctrine that the quaternion affords the only sufficient and proper basis for vector analysis is maintained by arguments based so largely on the faults and deficiencies which the author has found in my pamphlet, “Elements of Vector Analysis,” as to give to such faults an importance which they would not otherwise possess, and to make some reply from me necessary, if I would not discredit the cause of non-quaternionic vector analysis. Especially is this true in view of the warm commendation and endorsement of the paper, by Prof. Tait, which appeared in NATURE somewhat earlier (p. 225)..."
1. This exact issue is the subject of the following 1966 article, the abstract being: "A facet of the development of electromagnetic theory was the choice of a proper notation. This seemingly minor problem generated a large dispute from about 1880 to 1900, reaching a climax in a series of letters in Nature arguing about the relative merits of the quaternion formulation, due to Hamilton and supported by Tait, and the newer vector analysis of Gibbs and Heaviside. This quarrel was carried on at a violent level in many letters in Nature..." American Journal of Physics -- March 1966 -- Volume 34, Issue 3, pp. 202m “Vectors Versus Quaternions”—The Letters in Nature by Alfred M. Bork