of copper, heat, &c., gave 6.02 grains of sulphate of baryta: hence 10 grains of the salt would have afforded 8.6 grains of the sulphate, equivalent to 2.915 grains of sulphuric acid. Five grains, when heated with oxide of copper, gave 16.68 cubic inches of carbonic acid gas, equal to 7.772 grains, and equivalent to 212 grains of carbon. The water formed amounted to 1.2 grain, equivalent to 0.133 of a grain of hydrogen.
From these data, 100 grains of the salt would appear to furnish—
| Baryta | 28.03 | 78 | or 1 proportional. |
| Sulphuric acid | 29.13 | 81.41 | nearly two proportionals. |
| Carbon | 42.40 | 118. | approaching to 20 ditto. |
| Hydrogen | 2.66 | 7.4 | or 7.4 proportionals. |
| 102.22 |
results not far different from those obtained with the former salt.
I have not yet obtained sufficient quantities of this salt in a decidedly crystalline state to enable me satisfactorily to account for the difference between it and the flaming salt.
Attempts were made to form similar compounds with other acids than the sulphuric. Glacial phosphoric acid was heated and shaken in naphtha line, but without any particular results. A little water was then used with another portion of the materials, to bring the phosphoric acid into solution, but no decided combination could be obtained. Muriatic acid gas was brought into contact with naphtha line in various states, and at various temperatures, but no union could be effected either of the substances or their elements.
Very strong solution of potash was also heated with naphtha line, and then neutralized by sulphuric acid; nothing more, however, than common sulphate of potash resulted.
As the appropriation of a name to this acid will much facilitate future reference and description, I may perhaps be allowed to suggest that of sulpho-naphthalic acid, which sufficiently indicates its source and nature without the inconvenience of involving theoretical views.
Royal Institution, January 10, 1826.
