Comparative review of the way in which gold occurs in the North and South Islands of New Zealand.

Transactions and Proceedings of the Royal Society of New Zealand, Volume 2, 1869, Page 400

By J. Hector,M. D., F. R. S. (7.) “Comparative Review of the mode in which Gold occurs in the North and South Islands of New Zealand,” by Dr. Hector. The author rapidly reviewed the evidence of the nature of the matrix of the gold in Otago, Westland, and Nelson, and showed that in the North Island the essential conditions for the presence of gold are found in lines of dislocation, which by creating vertical bands of metamorphic rock, render auriferous, formations that never yield gold in the unaltered state. In the case of the Thames gold fields this vertical metamorphism had been accompanied by the eruption of igneous rocks of mesozoic age, and the metallic deposits have been still further concentrated by the eruption of tertiary volcanic rocks and thermal waters in the same district. Around Wellington there were no igneous rocks, and the gold that has as yet been found in the neighbourhood was derived from bands of slaty rock, in lines of dislocation that run in a north and south direction. With the assistance of coloured sections he explained the geological structure of the country around Wellington, and compared it with the Thames district, showing the absence of the most characteristic rocks which are associated with the gold there. He warned miners from expecting too much from the hard compact quartz reefs that traverse the indurated sandstone in the neighbourhood of Wellington, as most at least of them were of higher antiquity than the dislocations by which the gold has escaped from the deep seated rocks. In answer to Mr. Marchant, the author stated that at Taranaki similar volcanic rocks occur as at the Thames, but no slate rocks had yet been found associated with them, which, he believed was one essential required to complete the similarity of conditions; at the same time he had seen very likely-looking specimens from the Kaitaki ranges, but they had not yielded gold on analysis. The most marked junction of the trachytic rocks with the slates he had met with was on the west side of the Kaimanawa Range, south of Taupo Lake, and to which he had referred in a recent report. (8.) “On the Alluvial Gold in the Province of Wellington,” by J. C. Crawford, F. G. S. (See ante, p. 160.) The author described the probable distribution of alluvial gold, if any quantity exists in this province, and directed attention to the higher levels in the old terraces which skirt the ranges on the west, and also are found in patches in the wider valleys. Fourth Meeting. August 14, 1869. J. C. Crawford, F. G. S., Vice President, in the Chair. The election of the following new members was announced:—Sir David Monro, Mr. F. A. Krull, and Dr. Knight. Dr. Hector gave an account of some interesting results obtained in the Laboratory during the past month. He stated that the Urinui clay, which is being used in the reduction of the iron sand at Taranaki, had been found to possess no special properties either as a means of binding the sand mechanically, or as a flux, in both of which respects it is inferior to many other clays, as it only contains 30 per cent of clay, mixed with 65 per cent. of sand, and only 3 per cent. of lime. The specimens analysed had been forwarded by Mr. T. Kelly, the Provincial Secretary. A concretionary mass from the same clay had been found to contain 30 per cent. of lime. A vesicular rock which had been brought to the Museum by some diggers from Makara as a volcanic tufa or scoria, had proved to be a porous form of silica that had a very similar composition to the scinter deposited by the hot springs. It however in no respect resembles the auriferous tufa from the Thames District. Papers read:— (1.) “On the Extraction of the Poisonous Principles of the Tutu Plant (Coriaria ruscifolia),” by W. Skey. (See ante, p. 153.) By a process which he described he has discovered the poison to be a greenish oil, five minims of which administered to a cat produced, in the course of half an hour, a succession of violent convulsions, following at intervals of twenty minutes, accompanied by twitchings and contraction of the extremities, and dilation of the pupils. A large proportion of the dose was vomited within a few

minutes after it was administered, so that the poison must be extremely powerful. The quantity of the poison contained in the seed is 12 per cent. of the weight. Sir David Monro stated that he had seen the cat while under the influence of the poison, and that the symptoms exactly resembled those of a sheep that had eaten the Tutu plant, except that the hind legs of the cat seemed to be paralysed, while a Tuted sheep stood erect and had free use of its extremities, although unable to direct its movements. Specimens of the poisonous oil in different stages of its production were exhibited, and also the oil of the Karaka seed. (2.) “On two Seals of the genus Stenorhyncus, captured on the East Coast of Otago,” by J. S. Webb. (See ante, p. 28.) This paper described two specimens of seals which are in the Otago Museum. The author considered these to be a new species belonging to the genus Stenorhyncus which he proposed to name S. Crassicollus, his pricipal argument being that it is not Stenorhyncus Weddellii. The paper was illustrated by photographs of both specimens. Dr. Hector said that Mr. Webb had been misinformed as to this seal having been seen by him on the West Coast of Otago; the only one he had ever seen was at Moeraki, forty miles north of Dunedin. He pointed out that having had access to works which Mr. Webb had not been able to refer to, he had been able to determine the specimens described to be the young male and female of Stenorhyncus leptonyx, a species originally confounded with Leptonyx Weddellii. Mr. Webb is thus right in distinguishing it from that seal, which has not yet been found in New Zealand. Dr. Gray first distinguished these seals from specimens of two skins and skeletons, accompanied by a minute anatomical description of one captured in Wellington Harbour, and sent to the British Museum by Dr. Knox many years ago. Mr. Webb's description, measurements, and photographs all compared with that specimen. Dr. Hector exhibited a skull of one of the seals in question, prepared by Dr. Knox, and also the coloured drawings of specimens of both species of the seals referred to. (3.) “On the Anatomy of Naultinus punctatus,” by F. J. Knox, L. R. C. S. E. (See ante, p. 20.) This paper gave a minute description of the anatomy of the green lizard, in the course of which the author discussed the theory that the lizards have the power of reproducing the tails when they are broken off. He showed that the tail broke at a definite place marked both in the skeleton and on the cuticle, and expressed an opinion that no reproduction could take place. Mr. Buller remarked that Dr. Knox was mistaken in the species, and that the lizard he had described was Naultinus Greyii and not Naultinus punctatus. He further pointed out that in the Museum there were two specimens of lizards, in one of which the tail was forked, and in another, a small appendage had evidently been reproduced from a broken stump. Dr. Knox not being present, no explanation was afforded to account for these specimens. (4.) “Description of a new species of Ophisurus, found on the Coast of New Zealand,” by Dr. Hector, with “Anatomical Observations,” by F. J. Knox, L. R. C. S. E. (See ante, p. 34.) This paper described a species of serpent eel found in a tidal creek near Poverty Bay, and forwarded to the Museum by Mr. Campbell, R. M. Mr. Buller said he had never heard of this curious fish among the natives, and thought it must be very rare. Sir David Monro suggested that the specimen should be dissected, in order to determine the structure of the breathing apparatus, as there might be in this genus, the anatomy of which was imperfectly shown, an intermediate form of respiratory apparatus between the reptile and the fish, as had already been detected in the Protius, Axylotyl, and Syren. (5.) “On the Physical Features of the River Basins of the Wellington Province,” by J. T. Stewart. (See ante, p. 198.) This paper contained a minute description, and gave comprehensive details of the topography of the southern and eastern districts of the province, classifying the different water-sheds of the principal rivers and streams, and the relative drainage area of each, with comments on the valleys affected by floods from various quarters, and suggestions as to the districts in which it will be necessary to conserve the forest, in order to prevent alternations of droughts and floods in some of the valuable districts of the province. Mr. Crawford and Dr. Hector made comments on this paper, especially with regard to the distribution of the alluvial terraces, and the relative levels to which river terraces extend, which seem to be about 800 feet above the level of the sea, all over the province. (6.) “On Irrigation, as applied to the Culture of New Zealand Flax,” by J. C. Crawford, F. G. S. (See ante, p. 129.) The author pointed out the importance of irrigation to produce abundant crops of the flax plant, and described the different methods of applying it, and the districts in this province where they could be employed in a remunerative manner. He indicated the sandy tracts on the West Coast as being most available.

Fifth Meeting. September 18, 1869. J. C. Crawford, F. G. S., Vice President, in the chair. In accordance with clause 7 of the New Zealand Institute Act, it was necessary for the Society to appoint one of its members to vote in the election of Governors of the New Zealand Institute for the ensuing year, and Mr. J. C. Crawford was unanimously selected for this office. Paper read:— (1.) “On Thorough Drainage,” by Mr. Crawford. (See ante, p. 211.) Mr. Travers quite agreed with the suggestions made by Mr. Crawford, but thought there would be some difficulty in carrying out the system of thorough drainage in New Zealand, as he was afraid the proprietors of land would not work harmoniously in the matter. There should be an Act passed on the subject. Mr. Hamilton thought there would be a difficulty in draining the clay hills effectually, so as to produce percolation, as the superficial layer of soil is the most tenacious, and the water runs off the surface. (2.) “On the Mysticetus, or Right Whale,” by F. J. Knox, L. R. C. S. E. (See ante, p. 21.) A specimen of the head of Baloena marginata, Gray, was exhibited at the meeting, to illustrate this paper. The author gave a most interesting account of the habits of whales in general, and pointed out particularly the difference between the Mysticetus and the Rorquals, a drawing of which latter he exhibited. The use of the baleen was graphically described, especially as there were some fine specimens with the head above mentioned. (3.) “On the Upper Tertiary Fossils of New Zealand, with Lists of the Species,” by J. Buchanan. (See ante, p. 163.) (4.) “On the Tertiary Series of Oamaru and Moeraki, Otago,” by C. Traill, communicated by Dr. Hector. (See ante, p. 166.) Sixth Meeting. November 13, 1869. W. T. L. Travers, F. L. S., in the chair. The Honorary Secretary, Mr. R. Pharazyn, intimated resolutions received from the Governors of the Institute to the effect that papers intended for the “Transactions,” will in future require to be forwarded in the form in which they are read before the Society, and that authors will be entitled to receive twelve copies of their papers in a separate form.