552 Transactions. — Geology. 



bottom, and sides of the drive. It is very pale-green in 

 colour, and when exposed to the atmosphere for some time 

 gradually melts away, but if put under a glass case it keeps 

 its form and colour for many years. At this particular level 

 the mineral is very pleasing to the eye by caudle-light, as 

 nearly all the colours of the rainbow are reflected from its 

 surface. 



Ferrous sulphate also occurs at No. 1 level (210 ft.) — in 

 one case the characteristics being somewhat similar to that 

 already described, but in another place the reason for its 

 formation can be plainly seen. The water dropping from the 

 roof has formed stalactites of all shapes and size, some of 

 them very beautiful in form and colour, many reaching from 

 the top to the bottom of these old drives. The mineral is 

 very brittle ; and associated with it there is epsomite in large 

 quantities, depending from the roof and sides of the drive in 

 dense snow-white bundles like masses of fine-spun silk. The 

 mineral filaments possess a silky lustre, and vary from 4 in. to 

 8 in. long. 



In other parts of the mines there is a dark-green sulphate 

 of iron, which is only found in drives where the reefs or veins 

 have contained large quantities of iron-pyrites. The water- 

 dropping from the roof forms stalactites varying in size but 

 not in colour. This variety is much harder than the former, 

 and as brittle as glass. 



There can be no doubt but that this formation is caused 

 by the decomposition of iron-pyrites ; and, although sulphate 

 of iron is extensively used in the manufacture of manures, 

 some of this sent for analysis was found to contain so much 

 acid as to be of no commercial value. 



Its composition is as follows : FeS0 4 + 7 H. 2 0, equal to 

 sulphur-trioxide 28-8, iron-protoxide 25 - 9, water 45-3, in 100 

 parts. 



Akt. LVIII. — Notes on some Bocks from Campbell Island. 



By R. Speight, M.A. B.Sc. 



[Read before the Philosophical Institute of Canterbury.'] 



These rocks wex-e collected on Campbell Island by Mr. James 

 Gordon, who forwarded them by Dr. Cockayne to the Can- 

 berbury Museum, with the object, I believe, of having them 

 examined for gold. Campbell Island was formerly believed 

 to contain mineral deposits, and whalers stated that tin was 

 found there. Though there is no absolute impossibility that 



