them over oxide of copper, in hopes of results which might assist in suggesting correct views of their nature. They all appeared to be binary compounds of carbon and hydrogen, and the following Table exhibits the proportions obtained; the first column expressing the boiling temperature at which the products were distilled, as before mentioned; the second the hydrogen, made a constant quantity; and the third the carbon.
| 140° | 1 | 7.58 |
| 150° | 1 | 8.38 |
| 160° | 1 | 7.90 |
| 176° | 1 | 8.25 |
| 190° | 1 | 8.76 |
| 200° | 1 | 9.17 |
| 210° | 1 | 8.91 |
| 220° | 1 | 8.46 |
These substances generally possess the properties before described, as belonging to the bicarburet of hydrogen. They all resist the action of alkali, even that which requires a temperature above 250° for its ebullition; and in that point are strongly distinguished from the oils from which they are produced. Sulphuric acid acts upon them instantly with phænomena already briefly referred to.
Dr. Henry, whilst detailing the results of his numerous and exact experiments in papers laid before the Royal Society, mentions in that read February 22, 1821[1], the discovery made by Mr. Dalton, of a vapour in oil-gas of greater specific gravity than olefiant gas, requiring much more oxygen for its combustion, but yet con dens able by chlorine. Mr. Dalton appears to consider all that was condensable by chlorine as a new and constant compound of carbon and hydrogen; but Dr. Henry, who had observed that the proportion of oxygen required for its combustion varied from 4.5 to 5 volumes, and the quantity of carbonic acid produced, from 2.5 to 3 volumes, was inclined to consider it as a mixture of the vapour of a highly volatile oil with the olefiant and other combustible gases: and he further mentions, that naphtha in contact with
- ↑ Phil. Trans. for 1821, p. 136.
