3i6 



NATURE 



\August 4, 1887 



curtailment of the plan, and only the more important 

 minerals from the older rocks were completely analyzed ; 

 while for the bulk of the remainder, the properties of the 

 more important constituents, iron, phosphorus, and sul- 

 phur, were alone determined, and the presence of titanium 

 and manganese noted incidentally. The total number of 

 samples investigated was 1250, 53 being completely and 

 1 1 57 partially analyzed. The description of the methods 

 of analysis adopted, and the tabulation of the results, 

 occupy about a hundred pages, in addition to the 500 de- 

 voted to the geology and topography of the iron ore 

 mines and their statistics. 



The section devoted to coals, occupying eighty-seven 

 pages, is mainly statistical, and has a very valuable intro- 

 duction by Dr. Frederick Prime, Jun., which is perhaps the 

 best condensed account of the nature and distribution of 

 American coals that has yet appeared. A third section on 

 the Cretaceous coals and lignites of the North-West is 

 the result of an extensive exploration of the country 

 traversed by the Northern Pacific Railway, made by the 

 author subsequently to the completion of the census 

 work proper, in 1882. This work, under the title of the 

 Northern Transcontinental Survey, was suddenly stopped 

 after about ^20,000 had been expended upon it ; and in 

 order that the results might not be lost the observations 

 have been reduced, analyses of the coals have been 

 made, and a systematic memoir on the whole subject has 

 been produced, which, although not exactly in the place 

 where we should expect to find it, is too valuable an addi- 

 tion to American geology not to be welcomed in spite of 

 its incongruous surroundings. The statistics of the base 

 metals and minor minerals, occupying the remainder of 

 the volume, are now of comparatively little interest, as 

 these subjects have been treated from year to year in the 

 returns published by the United States Geological Survey, 

 and are available up to 1885. It must, however, be 

 remembered that it is only in census years that returns 

 from individual establishments can be obtained, and that 

 therefore the figures for those years may be regarded as 

 more authoritative than those of other dates. In any case, 

 statistics five years old are tolerably ancient history. 



In conclusion, we must call attention to the author's 

 introductory paper on the geographical and geological 

 distribution of the iron ores of the United States. This 

 is a masterly abstract of the main subject of the book, 

 and will be particularly useful to those who may wish to 

 acquire some knowledge of the basis of the American 

 iron industry without searching through the great mass of 

 reports and surveys in which most of the detailed informa- 

 tion is to be found. A plate of comparative sections of 

 the strata in the principal iron-ore producing States is 

 especially interesting as showing how the most important 

 ore deposits are confined to the older rocks, such as the 

 Archaean regions of New York and New Jersey, the 

 Huronian of Michigan and Wisconsin, and the great 

 stratified belt of haematite or "fossil ore" in the Clinton 

 group of the Upper Silurian ; while the most important 

 iron-bearing strata of this country and Western Europe, 

 the Lias and Lower Oolitic series, are entirely absent. 

 Although the great activity of the iron trade in 1880-81 

 was the cause of very energetic explorations, very few 

 discoveries were made in the older producing districts, 

 and it became evident that to make these it was necessary 



to go into new fields, and in any case the author considers 

 that the accessible rich ores may perhaps be practically 

 exhausted within the life of the present generation. It 

 will then be necessary to fall back upon the leaner kinds, 

 containing from 30 to 45 per cent, of iron, which are 

 known to exist in vast quantities, though generally far 

 removed from coal suited for smelting purposes. 



H. B. 



OUR BOOK SHELF. 



Theory of Magnetic Measurements. By F. E. Nipher, 

 Professor of Physics in Washington University. 

 (London: Triibner and Co., 1887.) 



This little work is intended to furnish information as to 

 the practical details of a magnetic survey. The descrip- 

 tion of the instruments used is poor. Full details as to 

 the necessary calculations are given. The directions for 

 the use of the instruments involve in a few cases un- 

 necessary precautions, while in others the method 

 suggested appears rather rough. Thus the statement 

 that it is advisable not to make any observations with a 

 dip needle till ten minutes after magnetization, is not, we 

 think, borne out by experience. On the other hand, the 

 suggestion that the vibrations of a declination needle may 

 be checked by the finger would be likely to mislead 

 beginners. It would have been better to describe the 

 method of bringing the magnet to rest by means of a 

 small auxiliary magnet. On the whole, English students 

 will probably find all that they want, and with more direct 

 reference to the Kew pattern instruments, in Stewart 

 and Gee's " Practical Physics," and are thus not likely to 

 make much use of Mr. Nipher's work. A. W. R. 



Studies in Life and Sense. By Andrew Wilson, F.R.S.E. 

 (London : Chatto and Windus, 1887.) 



Previous works of this kind by Dr. Andrew Wilson are 

 so well known, that a very few words will suffice to intro- 

 duce the present one to the notice of our readers. It 

 consists of a re-publication of essays on biological and 

 psychological topics, which the author has from time to 

 time contributed to sundry magazines. Although there 

 is little or no attempt at originality, the collection is well 

 calculated to prove of use and interest to general readers. 

 The style is everywhere entertaining, and the following is 

 a list of the subjects treated : — " Human Resemblances 

 to Lower Life," " Some Economics of Nature," " Monkeys," 

 " Elephants," " Past and Present of the Cuttle-Fishes," 

 " Migration of Animals," " The Problems of Distribution," 

 " Songs without Words," " The Laws of Speech," " Body 

 and Mind," " The Old Phrenology and the New," " The 

 Mind's Mirror," " What Dreams are made of," " Coinages 

 of the Brain," " The Inner Life of Plants," " An Invitation 

 to Dinner." 



Fermenti e Microti. Saggio di Igiene Antimicrobica 



Italo Gigholi. (Napoli, 1887.) 

 This book may be considered as marking a new departuj 

 in the teaching of hygiene. The enormous advances th^ 

 have been made of late years in the recognition of pat! 

 genie microbes, their life-history, and the conditioi 

 affecting them oneway or another, have added a lar| 

 and important chapter to the study of sanitary scienc 

 It is this particular subject in all its bearings on sanitaj 

 science which is treated in the volume by Prof. Giglic 

 The study of ferments, like yeasts, forms the introdi 

 tion : their life-history, physiological and chemical actic 

 are described, and, owing to the accurate knowledge tl 

 we possess of them— thanks in a great measure to tl 

 researches of M. Pasteur— they form a fit starting-poitf 

 in the study of schyzomycetes, bacteria, or microbe' 

 proper. 



