Dec. 30, 1875] 



NATURE 



165 



disgusting smelling precipitate of sodium sulphide is 

 produced." It will be new to chemists that sodium sul- 

 phide is a black substance insoluble in water. There are 

 a few well executed coloured lithographs, but the wood- 

 cuts, of which there are about forty, are ver>' rough. 



So much care and labour have e\ndently been bestowed 

 on the preparation of the book, that we regret to be com- 

 pelled to speak of it in terms of but faint praise. It is the 

 work of an earnest enthusiast who has discovered some 

 pretty reactions which might have at once become gener- 

 ally useful, had they been set forth in a clear and concise 

 form. 



THE ROCKS AND MINERALS IN THE 

 MELBOURNE MUSEUM 



A Descriptive Catalogue of the Specimens in the Industrial 

 and Technological Museum, Melbourne. By G. H. F. 

 Ukich, M.E., F.G.S. (Melbourne, 1875.) 



THE value of the collection of rock-specimens and 

 minerals in the Museum at Melbourne! will (be 

 much enhanced by the publication of this descriptive 

 catalogue, which has been drawn up by Mr. Ulrich 

 somewhat upon the model of the catalogue illustrating 

 the collections in the Museum of Practical Geology in 

 London. We learn from Mr. Newberrj^'s preface that 

 it originally formed part of the Report of the Museum 

 presented to Parliament in 1874, and it is now reprinted 

 with a view of making it more generally useful. Judging 

 from the catalogue itself, we should say that the collec- 

 tion of rocks and minerals from the province of Victoria 

 must be of an exhaustive character ; the varieties are 

 abundant, and embrace rocks of nearly every known 

 description. 



In drawing up this catalogue, the author has not 

 neglected the geological conditions under which the speci- 

 mens have been originally found ; and along with the 

 several varieties of granitic, plutonic, volcanic and sedi- 

 mentar}- rock-specimens are also described the distribu- 

 tion and characteristics of the masses from which the 

 specimens have been collected, together with their eco- 

 nomic uses. In this part of his work the author has 

 availed himself of the maps and reports of Mr. Selwyn, 

 late Director of the Geological Survey of Victoria — whose 

 important and successful operations in the field were 

 brought to a close about seven years ago, by a sudden fit 

 of parsimoniousness on the part of the Colonial Legisla- 

 ture. In describing the rocks, Mr. Ulrich has adopted 

 the system of classification laid down by Zirkel in his 

 Petrographie modified by the views of Von Cotta and 

 other petrologists. But, however valuable such a classi- 

 fication may be when it is in the power of the observer to 

 have constant recurrence to the aid of chemical analysis, 

 we consider that for the field petrologist it is only occa- 

 sionally available. The nice distinctions between the 

 several species of plagioclastic felspars are only to be 

 determined by laboratory analysis, and for the ordinary 

 observer a classification founded on the presence or 

 absence of quartz amongst the felspatbic rocks ; and on 

 the determination of hornblende, as against augite as the 

 basis of the pyrosenic rocks is sufficient. Daily expe- 

 rience, aided by microscopic examination, tends to show. 



that definite species amongst rocks are but limited in 

 number, and have little connection with geological age. 

 On this ground we object to such terms as " diabase," 

 with its several varieties mentioned in the Table of 

 Mixed Felspar Rocks, as well as " anamesite," " felspar 

 basalt," &c., though resting on the high authority of 

 Dr. F. Zirkel ; such being simply varieties of basalt or 

 dolerite. 



Again (in p. 24), several specimens are described under 

 the head of " porphyrite," with its varieties, in aU of which 

 quartz-grains are present. Now, if this term means any- 

 thing different from " porphyry," it means a quartzless 

 porphyry, as its author, Naumann, proposed. Zirkel's 

 definition is " quartzfreier orthoklas Porphyr." The pre- 

 sence of free silica, therefore, renders the name inappli- 

 cable ; and although the matter is of little consequence, 

 we refer to it to show the confusion which has arisen by 

 the introduction into petrology of an objectionable name, 

 and its use in a different sense from that intended by 

 the original proposer. 



Those portions of the catalogue relating to the occur- 

 rence of gold will be found of much interest, and must 

 prove useful to colonists and adventurers in search of the 

 precious metal. The upper Silurian strata rest discor- 

 dantly on the lower — as in the British I sles — and in these 

 latter are very numerous " veins, lodes, or reefs of quartz," 

 which traverse the beds, varying from one inch to 

 above 100 feet in breadth. According to Mr. R. Brough 

 Smyth's statistics for 1874, the number of these actually 

 proved to be gold-bearing amounted to 3,367, which was 

 being constantly added to owing to the energy of the 

 mining population. These reefs are the original source 

 of the gold, which is extracted directly from the quartz, 

 but more frequently from the detrital strata derived from 

 the denudation of the Silurian rocks, and now arranged 

 in three divisions of " Drift," of which the oldest is the 

 most auriferous. Associated with the gold grains are 

 minerals and precious stones in such variety and pro- 

 fusion as is only granted to a few favoured spots, amongst 

 which we notice the diamond, ruby, sapphire, topaz, 

 zircon, garnet, amethyst. Cairngorm, opal, &c., besides 

 metalhc ores, all jostling each other amidst the stones, 

 clay, and sand which would conceal their charms from 

 the unpractised eye. 



On the whole, the volume before us afibrds a remark- 

 able illustration of the similarity of the materials which 

 enter'into the composition of the earth's crust all over 

 the world, or at least in widely separated districts. Here 

 at the Antipodes we have a series of rock-specimens 

 exemplifying the rock-formations of Victoria, nearly every 

 one of which finds its representative in the British Islands. 

 We find similar granites, felstones, porphyries, diorites, 

 mica-traps, dclerites, basalts, schists, serpentines and 

 quartzites, sandstones, slates and limestones, and even the 

 rare " nepheline-basalt " of Philip Island and Port Ray 

 has its representative in the Wolf Rock, off the coast of 

 Cornwall, as Mr. Allport has recently determ'ned. As 

 regards the drawing up of the catalogue, the most scru- 

 pulous care has evidently been exercised, both in deter- 

 mining the nature of the specimens themselves, and in 

 identifying their localities ; while a very good idea of the 

 geological structure of the colony may be obtained from 

 a perusal of its pages. 



