The short answer is that you can not find it because it does not exist, Rayleigh never derived the "ultraviolet catastrophe". Chapter VI of Kuhn's book on the history of quantum mechanics reads: "The claim that black-body radiation should conform to the distribution law that has since been variously attributed to Rayleigh and Jeans was not made until 1905. But the main conceptual foundations for that claim can be found in a two-page note published by Rayleigh in the June 1900 issue of the Philosophical Magazine". Notes to the chapter give the reference as Lord Rayleigh,"Remarks upon the Law of Complete Radiation", The Philosophy Magazine, 49 (1900), 539-540; reprinted in John William Strutt, Baron Rayleigh, Scientific Papers, Vol. 4 (Cambridge, Eng., 1903), pp. 483-485. Here is the direct link to the Philosophy Magazine. I suspect that your citation is garbled.
Kuhn's note adds:"This paper has been carefully discussed by Hans Kangro in his Vorgeschichte des Planckschen Strahlungsgesetzes (Wiesbaden, 1970), pp. 189-192, and also by M. J. Klein in his "Max Planck and the Beginnings of the Quantum Theory," Archive for History of Exact Sciences, 1 (1962), 459-479, esp. 465-468. Both emphasize the importance of recognizing that it does not contain the Rayleigh-Jeans law". Here is more from the chapter:"Rubens and Kurlbaum compared a number of proposed radiation formulas with their data and concluded that Rayleigh's was satisfactory only in the limit where it coincided with
Planck's. Since the law, as proposed, was almost totally ad hoc, there was no further reason to take it seriously. Less than six months after it had been suggested, it was set aside". The historical importance of the paper, and of the "ultraviolet catastrophe" itself, has been greatly exaggerated by the "rational reconstruction" of history that turned it into the motivation for Planck's work.
There was no such motivation, see What was different about Planck's quantization of light compared to Einstein's? Planck derived his formula even before the Rayleigh's note, Rayleigh's two page argument was "partly theoretical and partly ad hoc", and "both cryptic and incomplete", according to Kuhn. Nobody knew of the "catastrophe" before 1905, although Lorentz already had some misgivings about the compatibility of classical electrodynamics with Planck's quanta. And even after Jeans's 1905 derivation it was still mostly Lorentz who cared about the mismatch (Planck and others dismissed it because they rejected the equipartition theorem on which Jeans relied). Only after Lorentz gave an airtight derivation of the Jeans law from the most general classical principles in 1908 did the issue enter the public consciousness, and even then the anxiety was more about the incompatibility of Planck's law with the classical physics than about the "ultraviolet catastrophe". The nickname was first circulated by Ehrenfest during the first Solvay Congress in 1911. For more references see How did Planck derive the black body radiation formula without using the Bose statistics?