Januaey 22, 1897.] 



SCIENCE. 



155 



times did not exist ; which is very far from se- 

 curing unanimous consent among geologists. 



In the same manner Mr. Hutchinson linows 

 a great deal more about the antiquity of man 

 than most geologists. He knows that the 

 human species is at the most not more than 

 25,000 years old. Surely he has with him in 

 that calculation the decided minority of scien- 

 tific students. To most, such a period seems 

 quite inadequate to account for known facts in 

 human history, apart from geologic questions. 



His book has ten quite pretty full-page fanci- 

 ful illustrations, designed by Cecil Alden, of the 

 Illustrated London News. They represent a 

 courtship of a warrior of the bronze age, the 

 building of Stonehenge by the dwarfs, etc. The 

 dozen chapters into which his subject is divided 

 take up the cave-dwellers and reindeer hunters 

 of the stone age, the ' myth ' of the great ice 

 sheet, changes of climate, the antiquity of man, 

 the men of the bronze age, the dwarfs and the 

 stone monuments, as dolmens, etc. 



In the line of popularizing science these chap- 

 ters are moderately meritorious. The leading 

 English works have been consulted, and es- 

 pecial respect is paid to such as do not oppose 

 received and conventional opinions, or do so 

 the least. Their writers are preferred by the 

 author as the correct exponents of modern re- 

 search. He makes considerable business out 

 the seeming contradictions of testimony and 

 the disagreements of specialists, when the facts 

 do not suit him (e. g., the Spy Man and the 

 Pithecanthropus). His reports, therefore, while 

 apparently judicial in tone, are not really so in 

 spirit. They are probably tinged by his avoca- 

 tion, as is almost inevitably the case. 



D. G. Brinton. 



University of Pennsylvania. 



Chemistry for Beginners. By Edward Hart, 

 Ph.D. Third Edition. Revised and greatly 

 enlarged. With 62 Illustrations and 2 plates. 

 Easton, Pa., Chemical Publishing Company. 

 1896. Small square 8vo. 245 pages. Price, 

 $1.50. 



In text-books of elementary chemistry we 

 have one of the most prolific fields of scientific 

 literature, and, so far from deprecating this fact, 

 each new book is to be welcomed as a contribu- 



tion^toward the solution of the difficult prob- 

 lem how best to teach chemistry to beginners. 

 This problem is as yet far from solution ; still, 

 comparing the text-books of to-day with those 

 of twenty, or even ten years back, it is appar- 

 ent that a distinct advance has been made. 

 This at least may be considered settled, that a 

 prominent place must be given to experimenta- 

 tion on the part of the student. What shall 

 be the relative order of theory and description 

 and the order of the elements in descriptive 

 chemistry is as far as ever from a final word, 

 nor will the latter point, in the opinion of the 

 writer, be settled until a natural order depend- 

 ent on the periodic system is reached. As 

 regards the former point, it must be kept in 

 mind that there are two classes of beginners — 

 those studying in secondary schools and those 

 of maturer minds in colleges ; a method of 

 treatment suitable for one would quite possibly 

 not be best suited for the other. 



The book before us is from the pen of an ex- 

 perienced teacher, and of this it gives abundant 

 internal evidence, and while written for begin- 

 ners in colleges is equally well suited for use 

 in high schools and academies. Ostensibly a 

 third edition, it is so completely revised and so 

 much enlarged that it is virtually a new book. 

 The order of treatment is as follows : Introduc- 

 tion on 'rusting ' of metals, oxygen, hydrogen, 

 water (with potability, purification, etc.), con- 

 stitution of matter, atmosphere, compounds of 

 nitrogen, carbon and its compounds, halogens, 

 sulfur, silicon, boron, phosphorus, arsenic, the 

 metals, the carbon compounds (sixty-six pages 

 on organic chemistry). 



The theoretical portion of the subject is taken 

 up from time to time, under appropriate com- 

 pounds or elements. While the elements are 

 considered, for the most part in the usual groups, 

 little or no regard is paid to the periodic law in 

 their arrangement. Equations for reactions are 

 very sparingly used, and the word valence 

 seems not to occur at all, although graphic 

 formulae are used, especially in the portion on 

 organic chemistry. 



The strong feature of the book is in experi- 

 mentation. Over two hundred experiments are 

 described, and it would be difficult to find a book 

 containing as many pertinent, well selected, 



