On the phosphates and arseniates [and other chemical essays] / [John Dalton].

  • Dalton, John, 1766-1844
Date:
1840
Catalogue details

Licence: Public Domain Mark

Credit: On the phosphates and arseniates [and other chemical essays] / [John Dalton]. Source: Wellcome Collection.

    16/60 (page 10)
    It is well known that the Biphosphate of Soda and Water consists of 36 or 37 Biphosphate of Soda, and 64 or 63 Water, expelled below a red heat in 100 parts. Dr. Clark has confirmed it, in Dr. Brewster’s Journal of Science, vol. 7, page 302. It will be remembered that Dr. Clark was the discoverer of the Pyrophosphates, and has written a very excellent treatise on the subject.— (See Dr. Brewster’s vol. 7, page 302, of the Edinburgh Journal of Science.) Dr. Clark determined that the Pyrophosphates constituted a new class of Salts. He finds the Pyrophosphates of Soda consist of “ Water expelled by the sand bath 40.63 Water expelled by a red heat —.09 Dry Pyrophosphate of Soda 59.28 100.—” Now 59.28 dry Salt: 40.72 Water (including the whole quantity of Water) : : 92 dry Salt : 64— = 8 atoms of Water, as in the Pyrophosphate of Soda. And in the former case as 44.5 Salt: 55.5 Water:: 52 Salt : 64 Water = 8 atoms, as in the simple Phosphate of Soda. Dr. Clark describes also a “ New Phosphate of Soda,” formed about 90° of heat ; this is the old Phosphate of Soda suffered to crystallize in 90° of heat. It has 2Q of the Water about it, and suffers as a loss, ! below 90,° from the fully crystallized Salt.