Its constituents are as follows:- 82.6928 3.8462 10.5768 100.0000 Colour, brownish-red. Amorphous. 44•15 10.00 Water ... 4.00 0:50 29.00 5.25 3.00 4.10 100.00 By comparing this analysis with the preceding, it is obvious that the oxide in this mineral is not the red, but the yellow oxide of lead, and that it owes its red colour to the oxide of iron which it contains. The proportion of oxygen is obviously over-rated in both analyses. 15. Spinell.-A specimen of spinell, from Oker, in Sudermanland, in Sweden, analysed by Berzelius, gave the following consti tuents : 100.00 16. Red Silicious Ore of Manganese -A specimen of this ore from Longbanshyttan, in Wermeland, in Sweden, analysed by Berzelius, was composed of 101.25 The excess of weight was owing to the manganese in the ore containing less oxygen than the black oxide, in which state it was obtained by analysis, 17. Sodalite.--Ekeberg analysed a mineral from Hefselkulla, in the province of Nerike, in Sweden, which, from his description of it, seems to have some resemblance to sodaliter, but its coristituents differ materially. It occurs in an iron-mine mixed with quartz. Its colour is greenish-grey; lustre, pearly and inconsiderable; principal fracture foliated with a two-fold cleavage; cross fracture granular, uneven ; translucent on the edges ; it scratches glass, but is scratched by steel; difficultly frangible; specific gravity 2.746. Its constituents were, Silica ... 46 Alumina 28.75 Magnesia 13.50 Oside of iron 0:75 Water 2.25 Soda 5.25 Loss 3.50 100.00 18. Black Garnet.-A specimen of black garnet from the ironmine of Svappavara, in Torneo Lappmark, analysed by Hisinger, gave the following constituents : 34.53 Lime .. 24.36 Alumina 1:00 Oxide iron 36.05 Volatile matter 0.50 Loss 3.56 Silica ... ated in hi Suderinu ving as 100.00 19. Sparry Iron Ore. A specimen of this mineral, from Riddarbyttan, in Wermeland, in Sweden, analysed by Hisinger, was composed of Red oxide of iron .. 63.25 Oxide of manganese 3.00 Lime .... 1.00 Carbonic acid 30.00 Water 1.75 20. Scapolite. A specimen of scapolite, from Sudermanland, in Sweden, analysed by Berzelius, was composed of Silica .... 61.50 Alumina 25•75 Lime.. 3:00 Magnesia 0.75 Oxide of manganese. 1:50 iron 1.50 Water 5.00 99.00 21. Cerite. This mineral, according to the last analysis of Hisinger, is composed of Oxide of cerium 68.59 Silica. 18:00 Lime 1.25 Oxide of iron 2.00 Water and carbonic acid 9.60 99.44 22. Spodumene.-Spodumene, from Utön, according to the same analyst, is composed of Silica .. *63.40 ... 67.50 Alumina 29.40 27.00 Oxide of iron 8:00 3.00 Lime ... 0.75 0.63 Volatile matter 0:53 0:53 Loss ... 2.92 1.34 100.00 100.00 The last of these analyses is by Berzelius. 23. I shall now subjoin a table of a number of Swedish minerals analysed by Hisinger: Silica 0.50 Lepidolite from Utön iron, a trace. 9.16 61.60 20.61 1.60 B 1.86 4.67 100.00 Me . anland, in "Silica Lime.. Malacolite, from Longbans- Magnesia hyttan Oxide of iron manganese Volatile matter 54.18 22.72 17:81 2:18 1.45 1•20. 100.00 y to the Oxide of iron Silica ... mine of Gillinge, in Suder-Oxide of manganese Volatile matter 51.50 27.50 5.50 0.77 11•75 2:98 100.00 Silica ... Alumina Oxide of iron minerals 100.00 29.8 21.6 1.0 4766 9:161 1986 461 100.0 100'00 Mealy zeolite from Fahlun Silica 60• 15.60 8:00 1.80 11.60 3.00 Loss .. 100.00 Red oxide of iron Phosphate of lime Iridescent "iron ore from Magnesia Grengesberg Stoney matter (Volatile matter 94.38 2.75 0:16 1.25 0:50 99.04 24. Swine-stone.--Hisinger and Berzelius have analysed various specimens of Swedish swine-stone. The following are the results of their labours :-Carbonate of lime 99.1 Transparent swine-stone from magnesia ... Garphyttan, in Nerike .... manganese. 0:9 iron 100,00 Gehlen has proposed two alterations in the present mode of analysing minerals; and, in his analysis of prehnite, he has shown that they inay be employed with advantage. 1. He substitutes carbonate of soda, instead of caustic alkali, for the original fusion of the mineral in a platinum crucible. He found that this method answers 'even in the analysis of corundum. ' 2. He substitutes carbonate of barytes for nitrate of barytes when our object is to obtain the fixed alkali which we suppose to exist in any mineral. He has found that this carbonate readily acts as a flux to minerals, and that it answers better than the nitrate of the same earth. |