February 2, 1906.] 



SCIENCE. 



185 



old methods and adopt new ones. The Eng- 

 lish journals are referred to almost entirely 

 throughout the book and one gets the impres- 

 sion that the continental periodicals have been 

 neglected. The table of contents now contains 

 a list of the tables throughout the book. This 

 will be found useful and will save time. On 

 the whole this book is certainly the best of its 

 kind in the English language and it will 

 always occupy an important place on the table 

 of the working chemist. F. L. 



A Text-hooh of Quantitative Chemical An- 

 alysis. By J. C. Olsen, A.m., Ph.D., 

 Professor of Analytical Chemistry in the 

 Polytechnic Institute of Brooklyn, formerly 

 Fellow of the Johns Hopkins University. 

 Pp. xix + 513. New York, D. Van Nos- 

 trand & Co. 



As stated in the preface, Professor Olsen 

 has not attempted to produce a reference book 

 for experienced analysts, but rather a book for 

 college students. Accordingly he has devoted 

 considerable space to theory and the explana- 

 tion of the various steps in an analysis and 

 has followed the sequence in which he presents 

 the subject to his classes. The first chapters 

 treat of ' General Operations and the Deter- 

 mination of Water,' then follow chapters on 

 ' Gravimetric Analysis of Metals, Acids, Al- 

 loys and Minerals,' ' Electrolytic Methods,' 

 ' Volumetric Analysis,' with special chapters 

 on ' Oxidation and Reduction ' and ' Precipita- 

 tion Methods,' ' Technical, Water, Oil, Fat 

 and Gas Analysis ' and finally ' Stoichiometry,' 

 and tables. There is not such a mass of facts 

 as in Fresenius and yet enough methods are 

 given for the teacher to choose good and inter- 

 esting work for everybody. The last few 

 chapters are particularly important, intro- 

 ducing as they do technical methods into the 

 ordinary course. It is to be regretted that 

 the author has not given in the first chapters 

 a fuller discussion of the application of the 

 ionic theory. Though apparently less essen- 

 tial, it is as necessary to the correct under- 

 standing of ordinary gravimetric methods as 

 to those that are purely electrolytic. Perhaps 

 the author assumes that no student is now 

 allowed to take up quantitative analysis until 



he understands the ionic theory, but a review 

 will do no harm. The directions are clearly 

 given throughout and the student is made to 

 feel that there is a reason for every step. The 

 author tries to do away with the ridiculous 

 practise of calculating results far beyond any 

 significant figure but goes to the other extreme 

 when he tells the student : " If an analysis is 

 carried out by a process or for a purpose in- 

 which an error of one per cent, may be present 

 no pains need be taken to secure greater ac- 

 curacy than this in any step of the process." 

 If this were logically carried out and there 

 were ten steps in the process a loss of one 

 per cent, in each step would certainly not give 

 a result within one per cent. The student 

 can be taught to work with all possible care 

 and accuracy without attributing too small an 

 error to his results. A chapter on stoichiom- 

 etry should not be necessary in a work of 

 this kind. Students with a proper under- 

 standing of the atomic theory and the simplest 

 mathematics should be able to make all neces- 

 sary calculations. It has evidently been the 

 experience of the author, as of all teachers of 

 the subject, that a majority of students need 

 special training in stoichiometry. There is a 

 fundamental fault somewhere in the student's 

 course either in chemistry or in mathematics. 

 Would it not be well for the teacher to force 

 the student to work out all these problems by 

 himself without any aid but the atomic theory 

 and the rule of three ? The reviewer hopes 

 that Professor Olsen will omit the chapter on 

 stoichiometry from the next edition of his 

 book and he feels that there will soon be a 

 second edition of so good a work. 



F. L. 



SCIENTIFIC JOURyALS AND ARTICLES. 



The leading article in the Journal of Nerv- 

 ous and Mental Disease for January is a 

 study by Dr. H. C. Gordinier of two unusual 

 brain tumors, one a multiple cylindroma of 

 the base of the brain, the other a neuro- 

 epithelioma of the choroid plexus of the fourth 

 ventricle. This is followed by Dr. Onuf, of 

 Craig Colony, with a study of a number of 

 cases of epilepsy presenting partly muscular 

 atrophies, partly defective muscular action 



