Chemistry, Theoretical, Practical, and Analytical: As Applied and Relating to the Arts and Manufactures, Volume 2

Voorkant
William Mackenzie, 1853
 

Wat mensen zeggen - Een review schrijven

We hebben geen reviews gevonden op de gebruikelijke plaatsen.

Inhoudsopgave


Overige edities - Alles weergeven

Veelvoorkomende woorden en zinsdelen

Populaire passages

Pagina 183 - ... the wind ; which might extend the sight of the philosopher to new ranges of existence, and charm him at one time with the unbounded extent of the material creation, and at another with the endless subordination of animal life ; and, what is yet of more importance, might supply the decays of nature, and succour old age with subsidiary sight. Thus was the first artificer in glass employed, though without his own knowledge or expectation. He was facilitating and prolonging the enjoyment of light,...
Pagina 183 - ... of life, as would in time constitute a great part of the happiness of the world ? Yet by some such fortuitous liquefaction was mankind taught to procure a body at once in a high degree solid and transparent, which might admit the light of the sun, and exclude the violence of the wind ; which might extend the sight of the philosopher to new ranges of existence, and charm him at one time with the unbounded extent of the material creation, and at another with the endless subordination of animal...
Pagina 183 - Who, when he saw the first sand or ashes, by a casual intenseness of heat, melted into a metalline form, rugged with excrescences, and clouded with impurities, would have imagined, that in this shapeless lump lay concealed so many conveniences of life, as would in time constitute a great part of the happiness of the world...
Pagina 245 - Fuchs's method is as follows :{ — " ' Clean and washed quartz-sand is mixed with the smallest quantity of lime which will enable the plasterer to place it on the wall. The surface is then taken off with an iron scraper, in order to remove the layer formed in contact with the atmosphere ; the wall being still moist during this operation. The wall is then allowed to dry ; after drying it is just in the state in which it could be rubbed off by the finger. The wall has. now to be fixed, ie, moistened...
Pagina 293 - Õ an hour, so as to mix thoroughly ; and then the zinc is added in small grains by throwing it on the surface, and stirring till it is entirely fused : the crucible is then covered, and the fusion maintained for about 35 minutes. The surface is then skimmed, and the alloy...
Pagina 246 - ... stereochrome over the real fresco (such as its admitting of being retouched and its dispensing with joinings), it appears that damp and atmospheric influences, notoriously destructive of real fresco, do not injure pictures executed by this process. " The following crucial experiment was made on one of these pictures : — It was suspended for twelve months in the open air, under the principal chimney of the New Museum at Berlin ; ' during that time it was exposed to sunshine, mist, snow, and...
Pagina 225 - ... has remained during about fifteen days in these ovens, they are opened, and the contents withdrawn. The plates have then to undergo all the operations of squaring, grinding, polishing, and silvering, in order to fit them for sale. The first process — that of squaring and smoothing the edges — is performed by passing a rough diamond along the surface of the glass, guided by a square rule; the diamond cuts to a certain depth into the substance, when, by gently striking the glass with a small...
Pagina 123 - ... charcoal that burned without flame, was blown up to whiteness by an explosive mixture containing the fire-damp, without producing its inflammation. An iron rod at the highest degree of red heat, and at the common degree of white heat, did not inflame explosive mixtures of the fire-damp; but, when in brilliant combustion, it produced the effect. The flame of gaseous oxide of carbon as well as of olefiant gas exploded the mixtures of the fire-damp.
Pagina 245 - The wall must be left in such a condition as to be capable of receiving colors when afterwards painted on. If, as frequently happens, the wall has been too strongly fixed, the surface has to be removed with pumice, and to be fixed again. Being fixed in this manner, the wall is suffered to dry. Before the painter begins, he moistens the part on which . he purposes to work with distilled water, squirted on by a syringe.
Pagina 245 - The formation of an insoluble cement by means of the water-glass, whenever the carbonic acid of the atmosphere acts on this substance, or whenever it is brought in contact with a lime-salt, has been applied by Fuchs to a most important purpose. The stereochrome is essentially the process of fresco...

Bibliografische gegevens