Chemistry and Physics. 305 



and thus cause matter to assume a condition which is devoid of 

 heat. In regard to that notice the editor has received from one 

 of the authors a letter which is too long to be inserted, but which 

 should be acknowledged here. It does not appear that objection 

 is made to our presentation of the main points of the theory, but 

 in relation to our opening remark, " Brinkworth and Martin, 

 with apparent seriousness, have made a curious extension of the 

 kinetic theory,^' the letter says, " Your abstractor appeared to 

 doubt the seriousness of the paper. I write at once to say that 

 in this matter we are in deadly earnest." The fact is, we 

 intended to convey the idea that the seriousness of the article 

 impressed us. Objection is made to our opinion that "Their 

 deductions are based upon an entirely unproven assumption," 

 and, in this connection, the letter refers to some points which are 

 to be brought out in a future article. It seems to us that no 

 injustice has been done to the authors as far as their preliminary 

 publication is concerned, and that further discussion of their 

 theory should be postponed until their more elaborate paper has 

 appeared. h. l. w. 



4. Elementary Chemistry, by F. W. Clakke and L. M. 

 Dennis. 12mo. Pp. 340. New York, 1902 (American Book 

 Company). — In preparing this little text-book the authors have 

 aimed especially to make it a means of training in the interpreta- 

 tion of evidence. Each generalization is made to follow the 

 evidence upon which it rests. The work is accompanied by a 

 laboratory manual, but a reasonable number of experiments, 

 nearly all of which are of the simplest character, are described 

 throughout the text. The book appears less dry and more inter- 

 esting than most of the works on the subject on account of the 

 constant attention which is paid to the application of chemistry 

 to human affairs and its utility in modern life. The authors have 

 done no more with the theory of ionization than to give it a very 

 brief mention. Although they consider this theory unsuitable 

 for discussion in a work of this kind, it seems probable that its 

 use in a simple manner would present no more difficulty to the 

 beginner than some of the theories which are introduced. It is 

 satisfactory to notice that the book contains a short treatise 

 (about 60 pages) on organic chemistry, a subject which is too 

 often omitted in books on elementary chemistry. Very few things 

 have been noticed in the work which seem unsatisfactory, but it 

 appears that the somewhat imaginary structural formula for the 

 double sulphate of magnesium and potassium (p. 202) is hardly 

 appropriate in such a book, and objection may be made to the 

 equation KClOg^KCl-FOg, because O3 is ozone. A mistake is 

 made in characterizino- lithium as the lio-htest solid known, for 

 solid hydrogen is mentioned in the book. h. l. w. 



5. Liquid Hydrogen and Helium; from the inaugural address 

 delivered at Belfast by Prof. James Dew^ar, President of the Brit- 

 ish Association. — * * * From this speculative divergency it is clear 

 no definite conclusion could be reached regarding the physical prop- 



