3i6 



NA TURE 



\^Fd 



Midway between pure science and its applications, we 

 find an important article on screws by Prof. Roland, 

 while in the various applications of science there is a 

 great wealth of admirable articles : railways, river engin- 

 eering, roads and streets, shipbuilding, public health, 

 are among the subjects of this nature treated of; and 

 always, so far as we can judge, by the best man. 



Of the contributions relating to geography, ethnography, 

 [y and statistics in these volumes, one of the most important 

 is Prince Krapotkine's part of the article " Russia," in 

 which he presents a very lucid account of the lead- 

 ing facts connected with his subject. Like all other 

 races, the Russians are, of course, to some extent a 

 mixed race. In the course of their history they have 

 taken in and assimilated a variety of Finnish and Turco- 

 Finnish elements. The author, however, points out that, 

 notwithstanding this process, the Slavonian type has main- 

 tained itself with remarkable persistency, Slavonian skulls 

 ten and thirteen centuries old exhibiting the same anthro- 

 pological features as are seen in those of our own day. 

 This he accounts for chiefly by the fact that the Slavonians, 

 down to a very late period, maintained gentile organisa- 

 tion and gentile marriage. Dealing with the circum- 

 stances of Russia at the present day, Prince Krapotkine 

 says that much still remains to be done for the diffusion 

 of the first elements of a sound education throughout the 

 Empire, and that the endeavours of private persons in 

 this field, and of the =cmstvos, are for political reasons 

 discouraged by the Government. The Government also 

 does what it can to check the movement in favour of 

 secondary schools where instruction would be based on 

 the study of the natural sciences. It prefers classical 

 gymnasiums. As every one knows, the natural sciences 

 are much cultivated in Russia ; and now the scientific 

 societies of old and recognised standing have to com- 

 pete with a group of new societies which have sprung up 

 in connection with the Universities. 



The geography and statistics of Prussia are dealt with 

 l)y Mr. J. F. Muirhead. Although somewhat hampered 

 by the fact that the physical features of Prussia had already 

 Iseen fully described under " Germany," Mr. Muirhead 

 has biiought together much valuable and interesting in- 

 formation both about the country and about the Prussian 

 people. He has, of course, a good deal to say about the 

 flourishing condition of education in Prussia. Of the 

 recruits levied to serve in the army in i882-S3the propor- 

 tion of men unable to read or write was only 2 per cent., 

 the rate varying from 975 per cent, in Posen to 0-03 in 

 Schleswig-Holstein, where there was only one illiterate 

 recruit among 3662. Mr. Muirhead contributes several 

 other geographical articles — among them, the one on the 

 Rhine, of which he thinks that probably the Tiber alone 

 is of equal historical interest among European rivers. 

 After a full account of the physical aspects of the river 

 and of its relations to industry and trade, he shows how 

 its whole valley was probably occupied at one time by 

 Celtic tribes, and how they were gradually displaced by 

 the advancing Teutons. 



Tlie topography and archa;oIogy of Rome have been 

 intrusted to Mr. J. H. Middleton, whose thorough know- 

 ledge of his subject has enabled him to make the most of 

 the limited space at his disposal. The article is devoted 

 mainly to those buildings of which some remains still 



exist. The plan of the Forum and nearly all the cuts 

 were measured and drawn by the author specially to 

 illustrate this article. 



Mr. George G. Chisholm gives a clear description of 

 the physical features, with an adequate account of the 

 agriculture, mineral wealth, and trade, of Roumania and 

 Servia. He has also a good article on Sardinia. There 

 is an excellent article on the St. Lawrence, by Sir Charles 

 A. Hartley, who points out that the great prosperity and 

 growth of Canada are owing to its unrivalled system of 

 intercommunication, by canal and river, with the vast 

 territories through which the St. Lawrence finds its way 

 from the far-off regions of the Minnesota to the seaboard 

 The statistics of Scotland have been carefully done by. 

 Mr. T. F. Henderson, but the scientific part of the article 

 " Scotland " is remarkable chiefly for Dr. Archibald 

 Geikie's masterly sketch of tha physical features of the 

 country and his summary of the facts relating to its 

 geological formations. The article on Siam, by Mr. Coutts 

 Trotter, contains all the information that ordinary readers 

 are likely to want about the physical characteristics and 

 resources of the country, and about Siamese law, education, 

 religion, and art. 



It will be evident from what we have said, that although 

 the " Encyclopedia " has already reached its twenty-first 

 volume, there is no falling off either in the care or in the 

 zeal of the editors. If all goes well, it is expected that the 

 whole work will be completed in four more volumes ; and 

 we may certainly say that the work has been conducted in 

 such an admirable manner that science will be a great 

 gainer by it, and that it is a production of which everybody 

 concerned may be justly proud. 



A TREATISE ON CHEMISTRY 

 A Treatise on Cheinis/ry. By Sir H. E. Roscoe, F. R.S., 

 and C. Schorlemmer, F.R.S., Professors of Chemistry 

 in the Victoria University, Owens College, Manchester. 

 Vol. III. "The Chemistry of the Hydrocarbons and 

 their Derivatives, or. Organic Chemistry." Part III. 

 (London and New York ; Macmillan and Co., 1886.) 

 T N the present instalment of the organic section of this 

 valuable work the authors begin the consideration of 

 the so-called aromatic compounds — the members of the 

 benzene series. 



The attention of chemists had long been directed to a 

 group of organic compounds remarkable for their richness 

 in carbon, and apparently unconnected in any way with the 

 ordinary " fatty compounds " — richer in hydrogen, and 

 correspondingly poorer in carbon — with which organic 

 chemistry chiefly busied itself. Many of the compounds 

 of this anomalous class occurred in Nature as odoriferous 

 principles ; this physical property was made the basis of 

 a rough classification, and the name " aromatic com- 

 pounds," originally employed in its strict sense, was ex- 

 tended so as to embrace the whole class, thus including 

 compounds destitute of aroma. Much was known, in a 

 more or less disjointed fashion, concerning these aromatic 

 compounds ; but no attempt had been made to solve the 

 problem of their constitution until Kekule, in 1865, pro- 

 posed his well-known benzene formula. This formula 

 has at no time, since it was first introduced, met with 

 universal acceptance ; and although, at the present day, 



