XVIII. Description of an apparatus for the analysis of the compound inflammable gases by slow combustion; with experiments on the gas from coal, explaining application

• Published in: Philosophical Transactions of the Royal Society of London
• Format: Article in Journal/Newspaper
• Language: English
• Published: The Royal Society 1808
• Subjects: Carbonic acid
• Online Access: http://dx.doi.org/10.1098/rstl.1808.0019; https://royalsocietypublishing.org/doi/pdf/10.1098/rstl.1808.0019

The aëriform compounds of hydrogen and carbon, which were already entitled to accurate investigation, as objects of scientific research, have derived an additional claim to the attention of the chemist, from their application to an important economical purpose, described in a late communication to the Royal Society. Yet there is, perhaps, no part of chemistry, the investigation of which is beset with greater difficulty, or with more numerous sources of error insomuch, that the actual state of the science enables us to attain scarcely more than approximations to the truth, and degrees of probability of greater or less amount. It was the object of the experiments, which are described in the following pages, rather to remove some of the obstacles, which present themselves to a successful enquiry into the nature of these bodies, than to acquire such facts, as may enable the chemical philosopher to decide the controverted question respecting their composition. Results, sufficiently multiplied and precise for this purpose, would require a larger appropriation of time, than I have the prospect of being able to bestow; and I can only on the present occasion, offer an example of the method, in which it appears to me that the analysis of this class of substances will be most successfully attempted. When a vegetable substance, composed (as may be assumed to simplify the statement) of oxygen, hydrogen, and carbon, united in the form of a ternary compound, is submitted to distillation, at a temperature not below that of ignition, the equilibrium of affinities, which constituted the triple combination, is destroyed and the elements, composing it, are united in a new manner. Those, which are disposed to enter into permanently elastic combinations, escape in the state of gas. The carbon, uniting with oxygen, either composes carbonic acid gas, or, stopping short of that degree of oxygenation, which is essential to change it into an acid, is converted into carbonic oxide. The hydrogen, combining with a portion of carbon, ...