is as follows:

Two shillings is due to the destruction of wrought iron, etc.

One shilling is due to the loss and waste of materials, of which three times the theoretical quantity must be employed.

Eightpence is due to the labor.

Fourpence is due to the fuel.

Mr. Castner seems justified in his claim to produce sodium at a shilling per pound in large quantities. The steel crucibles which have now been in use some time show but little wear, and indicate indefinite use in future, thus reducing the first item of cost in the older process to a fraction. There is hardly any appreciable loss or waste of materials, and from four pennyworth of caustic soda is ultimately obtained one pound of sodium. The labor is a very small item of expense, and the fuel consumed is less than one-third that used in the older process.

Seventy-five tons of fuel are required by the older method in producing one ton of sodium. From actual results a like amount of fuel will produce over three tons of sodium by Mr. Castner's process. The results from this new process are not obtained by calculations on paper, as the inventor has shown from actual working that his claims are well founded. The process is no longer an experimental one, the furnace now erected having a capacity of 120 pounds of sodium per day, which is probably more than is produced at any works now in existence. The production of sodium at one shilling a pound by this process may be considered an accomplished fact, which ultimately means cheapened aluminum and a solution of the problem that has so long engaged the attention of chemists and metallurgists.