Note 144 — Appendix. Cement for Earthenware. Restorations.

In such a case the hydrated oxide of tin is either present as such in the oxidized bronze, or it is a product of the reduction which has been prevented from falling to the bottom by the high sp. gr. of the potassium cyanide solution. It is also possible that finely divided tin in the reduced bronze may decompose the warm water into oxygen and hydrogen, forming a hydrated oxide of tin. Such a reaction would account for the formation of hydrogen. The hydrogen might at the same time remain occluded until allowed to separate by the cessation of the current and the temperature of the water.