protest against this _counterfeit coin_. I will therefore, at once, hand you the formula for COMMON WHITE BUFFER-RINGS, WASHERS, ETC. Grind 30 lbs. Java caoutchouc, Grind 18 lbs. Oxide of zinc, Grind 6 lbs. Carbonate of magnesia, Grind 6 lbs. Clean chalk or whiting, Grind 2 lbs. Flour of sulphur. This costs about 13 cents per lb., and is sold at 50 cents per lb., and, as you will perceive, contains about 110 per cent. of adulterating matter. Considering the mass of foreign substances in the above formula, (and yet sold under the name of “caoutchouc,” which _should be pure Java gum_, of less than half the density, for a great deal less than 50 cents gross price), one is almost astonished that the “gum-elastic” should retain any of its original liveliness, mixed up with so much dead weight; but so it is, as I shall show, by stating that a buffer-ring (4½ × 2½ × 1 ins.) of this quality exactly, and of the same size as those of which I gave the tonnage in your Magazine of the 24th of October, indicated, on the same being pressed to half an inch, 4½ tons on the dial. Of course the weight of the ring was fully double those then remarked upon, arising from increased density by adulteration. Pursuing the same subject of density, I have observed that these manufacturers have been compelled to charge _less than the actual weight_ of their goods, as the people at Berlin would not pay caoutchouc price for so much rubbish. This in the “good old red-lead time,” when the manufacturers, with more faith than judgment, considered they could not include too much of that metal, but they have since become more crafty and subtle, and use it less madly. I weighed a cylinder or spring some few months since, of which a like quantity are now in use by the London and North-western Railway, and, I expect, at their station at Wolverton, which contained at least, 100 to 130 per cent. of cheap, heavy adulteration; and yet they paid 1s. 6d. per lb. in quantity nett. The size was 6½ × 2½ × 4, and weighed close upon 6 lbs. I should say, if the charge had been 9d. per pound, no manufacturer could need a better trade, hence I have chosen to throw a little a “free trade light” upon the subject. The washer trade is a very lucrative one to the manufacturers, being principally cut from the spare or waste ends unavoidable in the make of springs, cylinders, and buffer-rings. I will now give you the formula for what is termed HYPO-CLOTH FOR WATER-PROOF COATS, &C. Grind 30 lbs. Clean Java gum, Grind 5 lbs. Lamp black, Grind 11 lbs. Dry chalk, or whiting, Grind 5 lbs. Sulphuret of lead. Costing about 12½ cents per pound.