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investigation of the case that I among others attempted it, but, for myself, was quite unable to realise the promise—in fact, I was unable to repeat the phenomenon as described. I got nothing to indicate that gold is nuclear to itself in solutions that contain organic matter, whether in a solid or in a dissolved form. The effect of such matters (organic), I found, was rather to disperse any gold it reduces than to concentrate such gold in a nuggety form. The results of these researches of mine were contained in a paper which was read before the Wellington Philosophical Society in 1872, and from this paper I make the following quotations : v "So far, therefore " —alluding to results just stated—" gold reduced from solution of its chloride by aid of organic matter, such as cork or wood, does not in the manner of its deposition exhibit such a notably selective power for metallic gold as the description of Mr. Daintree's results lead us to suppose. It does not, indeed, show any such selective process at all—that is, to a greater extent than can be attributed to the action of surfaces generally regardless of their nature; and in support of this I believe I am quite correct in stating that the whole sum of our experiences (omitting those of Mr. Daintree) is directly against this theory. ... So far as I am aware, we only produce by these means (organic matters) fine incoherent powder—minute crystals or films of exceeding thinness, nothing at all nuggety." I have since learned that Mr. Cosmo Newberry, late Analyst to the Geological Survey of Victoria, has confirmed the general accuracy of these assertions of mine by showing that gold is not nuclear to gold under the circumstances given by Mr. Daintree. Thus it seems that, after all, as yet we have got nothing more than the hazy, crude idea of the Old-World digger of the growth of nuggets in our drifts, an idea that many geological facts support, while others are antagonistic to it. And this growth of the nugget has been asserted by scientists to have been produced by nuclear action. Nuclear action, indeed ! alias nuclear force ! I take it to be of the same misbegotten fraternity as the centrifugal and centripetal forces of our oldest school-books —those learned terms that only obscured the truth they were invented to show. A long period of time again passed; the subject had apparently dropped out of mind, when a second time the scientific world was startled by a communication on the same subject, and for the same object. This time it was Mr. Charles Wilkinson, of the Geological Survey, and evidently the theory of Mr. Daintree, above detailed, had worked in his mind, and inspired its operations—the possible or probable nuclearity of gold for gold as in our drifts —that is, under natural conditions— had yet to be proved. But, as he thought, why limit the problem to gold? Why not try some of the native minerals that frequently exist along with gold ? Filled with this idea, he, after making numerous unsuccessful experiments, at length tried the metallic sulphides, and was handsomely rewarded. He had, as he thought, got the key to the problem. His results are given in a paper entitled "On the Formation of Gold Nuggets."! Shortly stated, this paper informs us that cupreous and iron sulphides, arsenical pyrites, galena, zincblende, stibnite, wolfram, and molybdenite act as gold does for nuclei to gold as reduced and precipitated from its chloride in water by organic matter. The accuracy of these statements thus given by Mr. Wilkinson was soon afterwards vouched for by Mr. Cosmo Newberry. Here, then, at last it appeared that this so-called " nuclear action " of a solid substance for gold had been sheeted home—that certain kinds of minerals can accrete, can attract, as it were, unto themselves the minute particles of gold that organic matters liberate from auric chloride, and mould these to the coherent, the crystalline, the massive form of the metal as we see it in the nugget; and thus the idea of a nuclear action of gold itself for gold, as Mr. Daintree's observation favours, receives apparently a further accession of proof. These results that Mr. Wilkinson obtained very much interested me, and I repeated them with such variations as my previous knowledge of the subject, and particularly of the dispersing effect of organic matter on gold solution, led me to make. Leaving out, then, the organic matter, I simply introduced a crystal of pyrites into the weak solution of gold trichloride in distilled water, when after a two-hours contact I found that this crystal was completely gilded over. The metal thereon was lustrous and coherent, and the crystal had all the appearance of solid gold. I afterwards found that the metallic sulphide arsenides generally as used without organic matter had the same effect as pyrites. Thus it was proved that derelict atoms of gold are not required for the accretion of gold on gold in the concrete form which obtains in our auriferous drifts.]: The explanation of this liberation of gold from its solution is simple. For this we must look upon the gold in solution as being a part of the combination—hydrochloride of oxide of gold, or hydrated trichloride of gold, the oxygen of which oxidizes both the sulphur and the metal of these sulphides so as to leave the gold upon them at the scene of action in the metallic state. But this, though explanatory of the reduction of gold, is not explanatory of the fact that the gold thus reduced is (the greater part at least) close and reguline, in place of its particles being more or less discrete, as they would be in the case of a deposit by simple reduction. This, I find, however, is explained by the fact that after the first few seconds of contact of the metallic sulphide with the auriferous solution the gold is deposited electrically —that, in fact, an electrical current is produced by the oxidation of the sulphide, and so the process is an electrolytic, an electrogilding one. In all this we have a proper rendering of the terms "nuclear action " or " nuclear effect " if we wish to keep them up in all their absurdity—gold can be nuclear to gold only as under the influence of an electric current. Thus it comes about as probable —indeed, as a certainty, 1 think —that if the nuggets and particles of gold in our drift formations do accrete gold —do exercise a " nuclear effect, as it is termed, for gold—it is under the directing influence of an electric current, or perhaps I should say

* Trans. N.Z. Inst., vol. v., p. 372. t Trans. Roy. Soo. Vict., vol. viii., art. ii. { Although I have some twenty years ago published this fact—viz., that organic matter is not necessary for the gilding of pyrites, &c, in this way—authors of works on gold do not correct the old idea by this later knowledge.