From E. D. Clarke   15 November 1821

From a careful analysis of 5 grains of Mr. Henslow’s mineral from Anglesea, independently of its crystalline form, it appears to consist of

Gr

Silica, 3 = 60

Alumina, 1 1/10 = 22

Soda, 5/10 = 10

Lime, 1/10 = 2

Water of absorption 1/10 = 2

Loss, Zn ² Iron ²

Grains — 4/100

Total 4. 8/10

without the Loss

w.ch equals 2/10

This Mineral gelatinizes in acid & is electric by friction. It is properly therefore anhydrous analcine, & quite a new variety.

E.D.Clarke