May 4, 1888.] 



SCIENTIFIC NKWS. 



423 



divisions are given delicately lithographed plates of the 

 characteristic genera of each group of Invertebrata as 

 represented in the greater periods, whilst the text is pro- 

 fusely illustrated by figures of the more important species 

 characterising the several lesser divisions or formations, 

 which together with the large and carefully executed 

 geological map of Europe attached to this volume simplify 

 and accentuate the teachings of what is perhaps one of 

 the most complete and lucid geological histories of the day. 

 We note that Professor Prestwich is very averse to 

 admitting that the Breccia of the.Permian Strata were de- 

 posited by the agency of ice, and his suggestion that 

 the grooves and striations often found on the rock-frag- 

 ments may be really slickenside surfaces and not glacier 

 striations, is deserving of consideration ; but when it is 

 remembered that many of these angular rock-fragments 

 weigh several tons, and have been transported from forty 

 to fifty miles from the parent rocks, it certainly seems a 

 more plausible theory than that these strata should have 

 been formed by what may be termed waves of transla- 

 tion, which is the theory Professor Prestwich favours. 



With reference to the probable duration of the 

 accessible coal measures of Europe, it is interesting to 

 note that a Royal Commission on which the author 

 served decided that at the present annual rate of con- 

 sumption (1871) there was sufficient coal to last 1,273 

 years, but allowing for the rapidly increasing rate of 

 consumption, the period may be reduced to 324 or 433 

 years, even allowing for being able to work coal at a 

 depth of 4,000 feet, the greatest depth at present worked 

 being about 3,000 feet. Professor Prestwich shows clearly 

 that the Globigerina Ooze deposited in the Atlantic is not 

 homologous with the chalk as at first was contended, 

 although it contains many calcareous Foraminifera which 

 occur fossil in the chalk, and the abundance of siliceous 

 Lithisted and Hexactinellid sponges attached by fine root- 

 lets to the surface of the Ooze presents another point of 

 analogy with the chalk, but as a matter of fact the great 

 bulk of the forms discovered on the " Challenger " 

 expedition are only distant analogies of the extinct 

 forms, and considering the bathymetrical limits to the 

 growth of existing sponges it appears impossible that the 

 chalk can have been deposited at the depth at which the 

 Globigerina Ooze is found. The more abstract, physical, 

 and cosmical problems have been relegated to the con- 

 cluding chapters, but they are by no means the least 

 interesting part of the author's contribution to the science 

 of geology, owing to the uncompromising way in which 

 theories are confronted by hard geological facts — a most 

 time-saving method of dealing with theoretical questions. 



The Fresh-waier Aquarium and its Inmates. A Guide to 

 the Arrangement and Care of Freshwater Aquaria* 

 By Dr. W. Hess, Professor in the Royal Technical 

 High School of Hanover. Stuttgart : Ferdinand 

 Enke. 

 The aquarium, or aqua-vivarium, as it should more 

 correctly be named, exists in two legitimate forms. It is 

 either a portable apparatus for the observation of water- 

 plants and animals, capable of being placed in a study, a 

 laboratorj', or a conservatory, or it is a structure for the 

 same purpose on a large scale fitted like those of 

 Naples, Roscoff, etc. Dr. Hess treats here exclusively of 

 the portable aquarium, that on the larger scale being for 

 the most part beyond the reach of private persons. The 



* " Das Siisswasser aquarium und Seine Bewohner. Ein Leitfaden 

 iir die Anlage und pflege von Susswasser aquarium." 



author confines himself also to fresh-water aquariums, 

 those for sea-plants and animals being more difficult to 

 manage, especially.in inland places. We find here, firstly, 

 very clear instruction for the installation, fixing, filling, 

 and management of an aquarium, of whatever shape and 

 size. Due emphasis is laid upon the quality of the water, 

 upon a proper proportion of animal and vegetable life to 

 each other, and to the size of the tank; upon aeration, the 

 removal of dirt from the bottom, the regular but not 

 excessive feeding of the zoophagous animals,the avoidance 

 of excessive light and heat. For want of attention to such 

 points many aquariums, as we have from time to time 

 the pain of observing, become neither instructive nor 

 ornamental, but simply nuisances, collections of dead 

 or dying plants and animals in polluted water. The 

 use of certain water-snails in browsing away 

 the tender green algag which are otherwise apt 

 to attach themselves to the glass and render it 

 opaque, is here mentioned. The caution is given 

 that if decomposing matter, i.e. the dead leaves of plants, 

 the cast-off skins of the animals and their excreta, is 

 allowed to accumulate at the bottom of the tank, one 

 unpleasant consequence will be a wonderful multiplication 

 of infusoria. Interesting as these creatures are as micro- 

 scopic objects, they are preferably kept in a separate 

 glass, since they rob the water of oxygen to a degree 

 injurious to the larger animals. 



An exceedingly elegant and commodious combination 

 of an aquarium and terrarium is here described and 

 figured. Around the top of an aquarium, which might, as 

 far as the principle is concerned be of any shape, is 

 fixed a tray extending outwards on all sides, so as to 

 form a sloping shore. This tray is covered with sand, 

 pumice, rock-work, and moss, and forms a snug semi- 

 aquatic retreat for tortoises, salamanders, etc. 



The plants and animals suitable for an aquarium are 

 described, in most cases figured. In every case the tem- 

 perature, food (where animals are concerned), and other 

 conditions are laid down. We can strongly recommend 

 this book to all lovers of water and swamp-plants and 

 animals if they read German. The betteran aquarium is 

 managed the more novel and accurate observations can 

 be made on the life-history of its inhabitants. 



Geometry in Space, containing parts of Euclid's wth and 

 12th Books, and some PropeHies of Polyhcdra and 

 Solids of Revolution, with E.xercises. Clarendon 

 Press Series. Edited by R. C. J. Nixon, M.A. 

 Oxford : Clarendon Press. 

 The author believes that the study of geometry in 

 space, as distinguished from geometry of two dimen- 

 sions only, is of great value, both as a mental disciphne, 

 and from a utilitarian point of view. He treats of 

 planes and solid angles, of polyhedra and solids of revo- 

 lution. An appendix is subjoined on the perspective of 

 solids. The whole treatise may be considered as a third 

 part of the author's " Euclid Revised." 

 • — *-;5*^<C*tf-» — 



Sanitary Value of Salt. — A writer in the Newcastle 

 Weekly Chronicle contends that the scarcity of salt and 

 the want of a saliferous atmosphere are among the pro- 

 minent conditions of unhealthy climates. He instances 

 the low sanitary condition of Siberia, where salt is 

 excessively dear and where the salt-bearing sea-breezes 

 are excluded. He considers that the prevalence of 

 leprosy among the poorer classes in India is due to the 

 high price of salt. 



