REMARKS.—Two patents for improvement in the manufacture of India-rubber, were granted in 1850. The first of which is for the use of the hypo-sulphate of zinc. This salt is prepared in the following manner. In a solution of caustic lime, potash, or other caustic alkali, boil flour of sulphur until the liquor is saturated, and into this liquid pass sulphurous acid gas, by any of the known means, for the purpose of obtaining a hypo-sulphate of the alkaline base. The liquid is allowed to stand and cool. The clear liquor is then decanted into a vessel containing a suitable quantity of a saturated solution of the nitrate or other analogous salt of zinc. On mixing these solutions the zinc is precipitated in a white powder, which is regarded as the hypo-sulphate of zinc. It is then washed on a filter, dried and subsequently ground in a paint-mill. Three pounds of this powder is mixed with ten pounds of India-rubber, and heated from three to five hours, at a temperature of 260° to 280°. The rubber, according to the inventor, will be found completely cured or vulcanized, and requires no free sulphur to be used in any part of the process, and no washing with alkali, as do the ordinary materials used for vulcanizing. Hence it is alleged that this process is adapted to the covering of silks and other delicate textures, and colored fabrics. Another patent was granted for a compound for vulcanizing India-rubber. The mode of treatment is much the same as the last, and produces the same results. The material is the artificial bi-sulphuret of zinc. The inventor claims the use of this composition _without the use of sulphur_ in any part of the process of manufacture, and the washing with alkaline solutions is not required, and is not used in this mode of manufacture. _Fifty-ninth_, to Fowler M. Ray, New York, Oct. 18, 1850. For vulcanized India-rubber springs. The “claim” as set forth in the employment of a ring, or rings, or disks, made of any of the preparations of caoutchouc, known under the various appellations of metallic or vulcanized rubber, as a substitute for metal or other kinds of springs, heretofore known and used, when such ring or rings, or disk or disks, or the equivalent thereof are applied, in manner substantially as described, whether made of metal or other solid or non-elastic substance. Also making the surfaces of all or either of the plates above and below, and interposed between the elastic rings or their equivalents, or the surfaces of the elastic rings or other of their convex, substantially in the manner and for the purpose specified. _Sixtieth_, to Jonathan Trotter, of New York, Dec. 3, 1850. For vulcanizing India-Rubber. The claim is the use and employment of zinc, in a manner whereby a hypo-sulphate or similar preparation of zinc is obtained in combination with India-rubber, for the purpose of curing or vulcanizing it, substantially as set forth with the use of free sulphur in any way in combination with the rubber.