Gowland has shown that, whatever may have been the practice of Japanese bronze makers in ancient and medieval eras, their successors in later days deliberately introduced arsenic and antimony into the compound in order to harden the bronze without impairing its fusibility, so that it might take a sharper impression of the mould.
This, when cast into forms and allowed to harden and dry slowly, comes out as transparent soap. A class of transparent soap may also be made by the cold process, with the use of coco-nut oil, castor oil and sugar.
It is deposited from water, which bubbles up from a number of springs in the form of horizontal layers, which at first are thin crusts and can easily be broken, but gradually solidify and harden into blocks with a thickness of 7 to 8 in.
Bedding plants should be placed to harden in sheltered positions out of doors towards end of month.
In the same way, washing the skin with spirit would tend to harden the epidermis and thus prevent the entrance of microbes; and the application of an ointment to an abrasion would have a similar action.
The results of applying tannic acid are to harden the pelt and discolour and weaken the fur.
The finest or flaky manna appears to have been allowed to harden on the stem.
Sow petunias in heat, and prick out and harden for bedding out; also gloxinias to be grown on in heat till the flowering season.
But from a study of Dalton's own MS. laboratory notebooks, discovered in the rooms of the Manchester society, Roscoe and Harden (A New View of the Origin of Dalton's Atomic Theor y, 1896) conclude that so far from Dalton being led to the idea that chemical combination consists in the approximation of atoms of definite and characteristic weight by his search for an explanation of the law of combination in multiple proportions, the idea of atomic structure arose in his mind as a purely physical conception, forced upon him by study of the physical properties of the atmosphere and other gases.
The board is then exposed to the sunlight till the lines dry and harden into the condition of gut.