Burning glass

MnOi- He called the gas vitriol air and reported that it was colourless, odourless and tasteless, and supported combustion better than common air, but the results did not appear until 1777 because of his publisher s negligence. Priestley s classic experiment of using a burning glass to calcine HgO confined in a cylinder inverted over liquid mercury was first performed in Colne, England, on 1 August 1774 he related this to A. L. Lavoisier and others at a dinner party... 

In 1694-95 Cosmus III, Grand Duke of Tuscany, made it possible for Giuseppe Averani and Cipriano Antonio Targioni of Florence to heat a diamond with a large burning glass. The gem was destroyed (255). Various modifications of this experiment were tried in Vienna and Paris (256). 

When he focused a burning glass upon natural substances, such as wood, cotton, or paper, in a closed glass jar from which the air had been pumped out, they emitted smoke but no flame. To make certain that no... 

He concentrated the heat from the sun on mercuric oxide by using a burning glass or lens. The heat decomposed the mercuric calx and a gas collected in the glass vessel. 

Fig. 2, Apparatus for carrying out calcinations, credited to Priestley [3]. The metal is contained in a porcelain cup N, placed upon the stand IK, under ajar A, in the basin BCDE, full of water the water is made to rise up to GH by sucking out the air with a syphon, and the focus of a burning glass is made to fall upon the metal...

A silk thread to make the book move and a burning glass hidden in your hand ... 

Homberg explored the issue of chemical composition systematically in a series of Essais de chimie presented to the Academy between 1702 and 1709. His approach combined various traditions then known and defies simple characterization. On the one hand, he sought to rehabilitate the doctrine of five principles, by separating them out in actual analysis with the burning glass, a new and more powerful furnace. He thus defined... 

This divergence of vision between a philosopher/chemist and an apothe-cary/chemist became more pronounced in the ensuing years with the use of the burning glass. 

With the Tschirnhaus burning glass, Homberg embarked on a series of experiments to unravel the nature of the sulphur principle. He expected that the new instrument would reveal the intimate composition of bodies at the corpuscular level, beyond the ordinary chemical analysis of distillation. He was already familiar with Du Clos s experiment with the old burning mirror. It proved to him in an incontestable manner that the matter of fire or igneous particles entered into the composition of bodies and augmented their weight. He thus attributed... 

The acid of sulphur was precisely the same as that of vitriol and alum, as Homberg had earlier predicted. It produced alum with simple earth, vitriol with an earthly and a metallic matter, and common sulphur with an earthly and a bituminous or inflammable matter. Homberg believed that the second component, a dense, bloody red oil, was the true sulphur or the inflammable part of common sulphur, carried in the minimal amount of distilled oil which served as a vehicle. The sulphur principle still eluded him, however. The third component, an earth, was extremely fixed (having lost the volatile component of oil) and nearly inalterable. Even when exposed to the burning glass, it only produced fumes without burning. 

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