ii8 



NATURE 



\ytine lo, iSSo 



particular of the so-called "Sparagmite" or fragmental 

 accumulations below the Primordial zone. He believes 

 that the older gneiss may include metamorphosed por- 

 tions of younger for,nations, in particular considerable 

 masses of the Primordial rocks. This question in another 

 form is discussed in Part IV., which treats of the geology 

 of Central Norway. To the oldest sedimentary forma- 

 tions, termed the Sparagmite series, a thickness of 2,300 

 Norwegian feet is there assigned. They consist of sand- 

 stones, conglomerates, schists, slates, and limestones. 

 Above them lie the Primordial beds, 2,900 feet thick, 

 composed of quartz-schists, mica-schists, " blue-quartz/' 

 sandstones, clay-slates, and limestones, among which are 

 found the earliest fossils {Dictyonema, Olenellns, &c.). 

 Above these rocks the unfossiliferous red sandstones and 

 conglomerates of the west coast (? Old Red Sandstone), 

 long since described by Naumann, close the geological 

 record until the deposits of the Glacial period. Dr. 

 Kjerulf brings forward many facts regarding the meta- 

 morphism of the older palaeozoic rocks in Central Nor- 

 way, and traces with clearness the passage of these rocks 

 into schistose and gneissose masses as they approach the 

 larger areas of granite. Part V. is devoted to a brief 

 e.\-position of the geology of the Trondhjem district. 

 Part VI. discusses the lithology of the eruptive rocks. 

 The various species and varieties of granite, syenite, 

 porphyry, gabbro, greenstone, olivine-rocks, &c., are here 

 described with remarkable succinctness alike as to their 

 composition and geological relations. Considering the 

 meagreness of the official equipment of the Geological 

 Survey, this portion of their work must be admitted to 

 be specially creditable to the Norwegian geologists. In 

 Parts VII. and VIII. information is given regarding the 

 structure of rocks and mineral veins. Some nature- 

 printed illustrations of rock-structure here inserted are 

 interesting. Slices of foliated, graphic, and porphyritic 

 granite, etched with hydrofluoric acid, have allowed the 

 more durable quartz to print its figure upon paper, and 

 the impression has then been photographed on wood and 

 cut into a woodcut. Some figures are also added to show 

 the coexistence of organic remains (graptolites, corals) 

 with crystals of chiastolite, vesuvianite, and other minerals 

 in metamorphosed Silurian rocks. 



A useful feature in the German translation is the 

 addition of an inde.'c, which is wanting in the original, 

 but which would have been still more acceptable had it 

 been even fuller than it is. The numerous woodcut sec- 

 tions enable a reader to follow the local descriptions in 

 the te.xt. But the addition of a good geological index- 

 map, such as that which accompanies the Norwegian 

 volume, would have been of much service, and might 

 perhaps have been given without any very serious increase 

 of price. But this is a defect which every geological 

 reader, at a httle cost to himself, can remedy by obtain- 

 ing the general map. He will find in Dr. Gurlt's version 

 of Dr. Kjerulf's memoir an invaluable compendium of 

 Norwegian geology, and will probably be induced to set 

 out himself to make a personal exploration of the sections 

 which are therein described. Should he be induced so 

 to do he will doubtless come to look back on his tour in 

 Norway as one of the most instructive as well as delight- 

 ful of all his geological rambles. 



Arch. Geikif. 



E UCAL YPTO GRAPH I A 

 Eucalyptographia : being a Descriptive Atlas of the 

 Eucalypts of Australia and the Adjoining Islands. 

 By Baron F. von Mueller, K.C.M.G., M. and Ph.D., 

 F.R.S., Government Botanist for the Colony of Vic- 

 toria. Decades i and 2. (Melbourne and London, 

 1879.) 

 1\ /r ATERIAL for the issue of this atlas was accumu- 

 ■1- ' J- lated at Melbourne now over thirty years ago, and 

 the study of this fine group of the myrtles has been 

 carried on ever since, as opportunities presented them- 

 selves by Dr. Mueller. Still the subject was so large and 

 the perple.xities surrounding it so many that even now he 

 offers his observations in these decades as only fragments 

 toward a some day complete monograph. The difficulties 

 surrounding the study of this group are many. There is 

 the large number of species, the genus Eucalyptus being 

 surpassed in this respect only by Acacia. The resem- 

 blance of many specific forms is apt to deceive one ; the 

 fruits, and more 'especially the flowers, are often far out 

 of the reach of the ordinary traveller, even though he 

 might in his enthusiasm not object to climb for a con- 

 siderable height into the trees ; and then the species 

 themselves are widely distributed over ^the whole of the 

 Australian continent and Tasmania, some even extending 

 to the Indian Ocean Islands, though, it may be added, 

 none occur in New Zealand. 



Mr. Bentham's grouping of the species has been, with 

 some trifling modifications, adopted by the author, and 

 the Government of West Australia has borne the expense 

 of issuing these two decades, which contain descriptions 

 of some of the most important timber trees of the great 

 western colony. It is to be hoped that some of the other 

 colonial governments may follow this good example, and 

 so help on the publication of the work. Perhaps even our 

 own Royal Society might see their way to help it by a 

 grant in aid out of the fund placed at their disposal by 

 Parliament for promoting scientific research. 



The economic value of these eucalypts needs scarcely 

 to be insisted on. Not only do they yield excellent hard 

 timber, but as products we find enumerated oils, tars, 

 acids, dyes, tan, and potash. What magnificent forest 

 trees are to be found among them will appear from the 

 description of some of the species figured in these parts. 

 One (E. goniocalyx) is mentioned as growing on low or 

 hilly woodlands up to about 3,000 feet, and attaining in some 

 of the forest valleys a height of 300 feet, with a stem 

 diameter of not rarely six feet, and sometimes even ten. 

 The timber of this species is described as hard and tough, 

 exceedingly durable, lasting well when buried under- 

 ground, not warping, and difficult to split. Another 

 species (£■. kitcoxylou) known as the iron bark tree, or 

 white gum tree, grows to a height of 200 feet, has a timber 

 of great hardness, durability, and of extraordinary 

 strength. On being burnt for charcoal it yielded 

 28 per cent, of superior stuff, 45 per cent, of crude 

 pyroligneous acid, and 6 per cent, of tar. An excellent 

 packing paper has been prepared from the inner layers of 

 the bark, as can indeed be done from the inner bark of 

 most eucalypts, and the leaves yield a volatile oil to the 

 extent of about I per cent. 



The genus thus abounding in useful products is not 



