On page 149 of the present volume of the SCIENTIFIC AMERICAN, thore is a paragraph having the above caption, in which it is stated that " the water of our earth would form a globe of about sixty thousand miles in diameter." There is a mistake in the number, which should read, " about four hundred miles." If we allow the water on the globe to cover two-thirds of its surface, and suppose a general depth of about two hundred fathoms, it would give as the solid contents 33,513,246 cubic miles, from which data we calculate that this quantity of water can be contained in a sphere of the above diameter. There are many curious facts connected with the solid matter found in solution in the water of oceans and seas; for example, gold and silver are generally present in sea water, although in the most minute quantities, and in fact, traces of nearly every other metal have been found. This is accounted for by the supposition that many mineral veins must be exposed to the action of the water on the rocks which form its bed; and as there is an abundance of that universal decomposer, chlorine, it attacks and dissolves small quantities. We believe that Dr. Percy, the metallurgist, of England, was the first who demonstrated the presence of gold in sea-water. In regard to errors which from time to time creep, almost unawares, into the columns of every journal, we would state that they occasion us much annoyance, and we are glad to correct them. They seem almost unavoidable at times when the printer is clamorous for shorfitems to " fill up."