NOTES:

1. The average price per ton of pig iron, bar iron, and coal, together with the price paid for labour at the works, for a long series of years, would be very valuable, and I shall feel much indebted to anyone who will favour me with it for any, even short, period.

2. The accurate proportions are, by measure, oxygen 21, azote 79.

3. A similar reasoning may be applied to lamps. An Argand burner, whether used for consuming oil or gas, admits almost an unlimited quantity of air. It would deserve enquiry, whether a smaller quantity might not produce greater light; and, possibly, a different supply furnish more heat with the same expenditure of fuel.

4. Deutoxide of hydrogen, the oxygenated water of Thenard.