£ s. d. Grind 15 lbs. Java Caoutchouc at 7d. 0 8 9 Grind 15 lbs. Para Caoutchouc at 2s. 1 10 0 Grind 15 lbs. Oxide of Zinc at 3d. 0 4 0 Grind 16 lbs. China or Cornwall clay 0 0 3 —— Total, 16 lbs. 28 oz. Yellow Sulphur 0 0 3 Mill-costs at 3d. per lb., on 73 lbs. 0 18 3 —— —— —— Total, 3 5 3 Costs therefore, 10½d. per lb. _The above is 110 or 112 per cent. of adulteration._ I should here remark, there is also a kind of packing in use, which perhaps is practically best known as “Rag Packing,” made principally from the useless cuttings in the manufacture of India-rubber coats, where the gum is run or spread on calico foundations, which is usually the case with water-proof garments offered for sale at the shops. It is made as follows: Rag packing for valves, bearing springs, or in sheets of any thickness, where less elasticity is required, and great pressure. £ s. d. Grind 35 lbs. Useless scraps, say 0 3 0 Grind 18 lbs. Black Lead, at 2¼d. 0 3 4½ Grind 16 lbs. Java Gum, at 7d. 0 9 4 Grind 1 lbs. Yellow Sulphur, 0 0 1½ —— —— —— —— Total, 70 lbs. Mill-costs at 4d. per lb. on 70 lbs. 1 3 4 —— —— —— Total, 1 19 2 This is sold at 2_s._ per lb. in very large quantities, or 1_s._ 6_d._, if a shrewd man, net, or a small discount for cash. Our gardens, fire engines, brewers, and pump-makers (for suction, &c.,) have found the value of this gum, and the following is the form used with success, and perhaps the adulterations are the best substitutes for pure caoutchouc that the cheap compound market offers. £ s. d. Grind 20 lbs. Java, at 7d. 0 11 8 Grind 10 lbs. Para, at 2s. 1 0 0 Grind 14 lbs. White Lead, at 3d.} 0 7 0 Grind 14 lbs. Red Lead, at 3d.} Grind 1½ lbs. Yellow Sulphur, 0 0 3 —— Total, 59 lbs. at 3d. per lb., Mill-costs, 0 14 9 —— —— —— Total, 2 13 8 Consequently costs 10½d. per lb.