174 



NATURE 



\_Dec. 25, 1879 



to warrant the extreme praise of not being overdone. 

 But we confess to being more pleased with certain 

 parallel plates on the Lepidoptera of the Dutch Indies 

 that have recently appeared in the Tijdschrift voor Ento- 

 mologie (the publication of the Entomological Society of 

 the Netherlands). Our English plates of butterflies and 

 moths too often remind us irresistibly of the sheets of 

 figures of these insects (often beautifully executed) that 

 appear in the shop-windows to be utilised as "scraps," 

 or in any way the purchasers may think fit. That in 

 the majority of cases they serve to identify the species 

 is probable, but they lack the slightest delineation of 

 structural details other than those shown in the general 

 outline of the body and wings. The figures of moths are 

 innocent of legs, innocent of neural details, innocent of 

 palpi (unless these organs be more than usually pro- 

 minent), and equally innocent of other indications that 

 are now often considered of importance. 



Many of the species here described and figured have 

 their evident palaearctic analogues ; but, in the absence 

 of a complete list of those found by Mr. Atkinson and 

 other Indian observers, it is impossible to form an idea 

 as to the general nature of the Himalayan lepidopterous 

 fauna. R. McLachlan 



MINERAL DEPOSITS 

 Die Lehrc von den Lagerstatten der Erse; cin Zweig dcr 

 Geologie. Von Dr. Albrecht von Groddeck. 8vo. 

 pp.350. (Leipzig, 1879.) 



IN this volume the phenomena characteristic of mineral 

 deposits are concisely treated in a manner suited for 

 students' use. The descriptive matter is arranged under 

 three heads, the first dealing with the forms of lodes, 

 beds, &c, and their relations to the containing walls or 

 "country" rocks, the second with the contents, or more 

 particularly, with the distribution in the deposits them- 

 selves of such contents in the shape of valuable minerals ; 

 while the third is a " system of mineral deposits " arranged 

 under different sub-sections, such as original and recon- 

 structed deposits, beds stratified and massive, veins and 

 other deposits filling cracks and hollows, &c. ; each parti- 

 cular case being referred to a so-called type bearing a 

 special name. The fourth and final section contains a 

 theory of the origin of mineral deposits in general. 



Of the matter contained, much is reproduced from the 

 late Dr. B. von Cotta's " Lehre von der Erzlagerstatten," 

 the last edition of which was published in 1861, the 

 remainder being for the most part derived from papers by 

 various authors that have appeared for the last twenty 

 years, in different German journals, devoted to geological 

 and mining matters. 



The principal novelty is the arrangement of the third 

 part, and this is not very satisfactory, the fifty-six types 

 making up the " System " being based partly on structural 

 and partly on topographical considerations, the grouping 

 being too artificial to be of any real geological value. 

 Thus, for example, deposits of chromic iron ore in ser- 

 pentine are said to belong to the " Wooded Peak'" type, 

 because an occurrence of this kind has been reported from 

 a place bearing that not very distinctive name in New 

 Zealand ; the famous old mines of Chessy and Monte- 



catini are examples of the Mednorudjansk type, whose 

 " characteristic " is given as follows : " Pyritic ores . . . 

 in unstratified (massigen) rocks oftenest Diorite Gabbro 

 and Olivine rocks (serpentine)/' This particular deposit, 

 named as the type perhaps better known as the Nishne 

 Tagilsk malachite mine does not, however, occur in un- 

 stratified rocks, but in a mass of chloritic, argillaceous, 

 and talcose schists, inclosed in upper Silurian limestones ; 

 the author having been led into a mistake by not properly 

 looking up his authorities, the account relied upon being 

 one published in a German journal twelve or thirteen 

 years ago. 



In another case, the Tellemarken-Cornwall type, the 

 characteristic is " Lodes in sedimentary rocks, prepon- 

 derating contents quartz and copper ores in varying 

 proportions, less common are barytes, carbonates, and sili- 

 cate of zinc, tin-stone, galena, &c." The examples given 

 of this type appear to show that the copper ores of Telle- 

 marken are not in veins in stratified rocks, but in quartz 

 strings in granite dykes, a tolerably common class of 

 occurrence in Scandinavia, and about as much unlike the . 

 ordinary type of Cornish lode phenomena as can well be 

 imagined. 



Many other examples might be adduced of the in- 

 congruities arising from the author's method of classifi- 

 cation. 



The accounts of the different districts are very dispro- 

 portionate in value, especially in non-German countries. 

 Thus Cornwall is dismissed in a page and a half, re- 

 produced from Cotta's work, and the whole of the car- 

 boniferous limestone lead regions of Central and Northern 

 England are included in a word or two about Derbyshire 

 and Cumberland, the Silurian districts of Wales not receiv- 

 ing any notice. Iron ores are still more capriciously 

 treated, the thin, stratified, spathic and clay band ores of 

 Westphalia taking the first place, while the mighty deposits 

 of Styria are allowed eight lines. No mention is made of 

 either Mokta-el-Hadid, Hodbarrow, or any other of the 

 great mines in the Furness, Ulverstone, or Whitehaven 

 districts, Sommorostro or any other of the Bilbao mines ; 

 and, generally speaking, the great sources of supply to the 

 iron-smelters in Western Europe are conspicuous by their 

 absence. Against this we have to set tolerably complete 

 notices of the iron ores of the United States, derived 

 for the most part from Dr. Wedding's Pennsylvanian 

 Exhibition Report. 



The work being primarily intended for the use of 

 German students may perhaps account for the circum- 

 stance that in the references only German writers are 

 noticed, and this is so completely carried out, that in the few- 

 cases where an English or American authority is named, 

 the titles of their works are not given. This is the more 

 to be regretted, as the use of original memoirs might in 

 some cases have prevented the appearance of errors in 

 the text, obviously due to the second-hand sources of 

 information usually relied upon by the author. The 

 careful study of a single good memoir, such as that of 

 the late Prof. Axel Erdmann on the Dannemora Mines, for 

 example, would probably be of more value as a means of 

 preparing a student for recording original observations, 

 than the most complete knowledge of the types of the 

 very artificial system contained in the work. 



