Note 109 — Chapter XI · TO HEKLA AND THE GEYSIR IN HAUKADALR.[87]

Everywhere we found leaves laminated with silicious deposit, but no trace of shells, even though we sought them under the turf. The composition of Geysir water will illustrate Forbes. In 1000 parts of water there are 0·5097 of silica, whereas the rest, carbonates of soda and ammonia, sulphates of soda, potash, and magnesia, chloride and sulphide of sodium, and carbonic acid, amount only to 0·4775, Out of the latter, again, soda represents 0·3009, and sodium 0·2609; silica and soda are therefore the constituents. The specific gravity is 1000·8 (Faraday).