On this subject I note the recently published opinions of Professor Lobley, a gentleman whose scientific reputation entitles his utterances to respect, but who, when he contends that gold is not found in the products of volcanic action is, I venture to think, arguing from insufficient premisses. Certainly his theories do not hold good either in Australasia or America where gold is often, nay, more usually, found at, or near, either present or past regions of volcanic action. It is always gratifying to have one’s theories confirmed by men whose opinions carry weight in the scientific world. About twenty-four years ago I first published certain theories on gold deposition, which, even then, were held by many practical men, and some scientists, to be open to question. Of late years, however, the theory of gold occurrence by deposition from mineral salts has been accepted by all but the “mining experts” who infest and afflict the gold mining camps of the world. These opine that gold ought to occur in “pockets” only (meaning thereby their own). Recently Professor Joseph Le Conte, at a meeting of the American Institute of Mining Engineers, criticised a notable essay on the “Genesis of Ore Deposits,” by Bergrath F. Posepny. The Professor’s general conclusions are: 1. “Ore deposits, using the term in its widest sense, may take place from any kinds of waters, but especially from alkaline solutions, for these are the natural solvents of metallic sulphides, and metallic sulphides are usually the original form of such deposits.” 2. “They may take place from waters at any temperature and any pressure, but mainly from those at high temperature and under heavy pressure, because, on account of their great solvent power, such waters are heavily freighted with metals.” 3. “The depositing waters may be moving in any direction, up coming, horizontally moving, or even sometimes down-going, but mainly up-coming; because by losing heat and pressure at every step such waters are sure to deposit abundantly.” 4. “Deposits may take place in any kind of waterways--in open fissures, in incipient fissures, joints, cracks, and even in porous sandstone, but especially in great open fissures, because these are the main highways of ascending waters from the greatest depths.” 5. “Deposits may be found in many regions and in many kinds of rocks, but mainly in mountain regions, and in metamorphic and igneous rocks, because the thermosphere is nearer the surface, and ready access thereto through great fissures is found mostly in these regions and in these rocks.” These views are in accordance with nearly all modern research into this interesting and fruitful subject. Among the theories which they discredit is that ore bodies may usually be assumed to become richer in depth. As applied to gold lodes the teaching of experience does not bear out this view.