416 



SCIENCE. 



[N. S. Vol. III. No. 63. 



about diatomic alcohols, acids aud ammonias. 



* * * * « 



Tlie substances first studied are cyanogen, 

 the ferrocyanides, the sulphocyanides, the cyan- 

 amides * * * * * urea and some of its ' 

 compounds. Having mastered these simple 

 subjects, the student is ready for methane and 

 its derivatives. About one-half of the volume 

 is given to the compounds of carbon. The facts 

 are clearly presented, a good selection of com- 

 pounds has been made, and recent work and 

 theories receive due attention. 



The same goodjudgment has been shownin dis- 

 cussing the other elements and their compounds. 

 A more careful revision of the text would have 

 removed some inaccurate statements. The 

 synthesis of oxalic acid in 1868 can no longer 

 be called recent, nor is it true, as stated on 

 page 236, that nitrogen forms only one com- 

 pound with hydrogen. 



The use of such trivial names as potassa, caus- 

 tic potassa, soda, gelatinous alumina and others 

 is often exasperating and sometimes leads to in- 

 correct statements. Soda is defined as sodium 

 carbonate, but on page 353 we are told that soda 

 produces, in salts of lead, a precipitate that is 

 soluble in an excess of the reagent. With the 

 general correctness and clearness of statement 

 no fault can be found, and, as an elementary 

 book of reference, this new edition should win 

 new friends. L. B. Hall. 



Principles of Metallurgy. By Aethur H. 



HiORNS. Macmillian & Co., New York. 



1895. 12mo., 388 pp., 144 illustrations, 



cloth binding. Typography and paper of 



good quality. 



It was the authors intention to prepare for 

 those who do not have ready access to the 

 journals of scientific and industrial societies 

 an abridged account of the modern methods of 

 extracting metals from their ores. An object 

 worthy of attainment but in this instance not 

 crowned with success. 



The arrangement of the work is as follows : 

 The physical and chemical properties of the 

 metals and their alloys occupy the opening 

 chapters, after which several chapters are de- 

 voted to general metallurgy, discussing fur- 

 naces, fluxes and fuels. Iron and steel occupy 



the greater part of the work, followed by 

 chapters on silver, gold, lead, copper, zinc, tin, 

 aluminum, mercury, antimony and bismuth. 

 While each division of the subject contains much 

 of value, the work is to be criticised from the 

 fact that much of the greatei' value is omitted. 

 By greater value is meant modern practice. 

 There is not a chapter that could not be im- 

 proved in this respect. 



Metallurgy has been defined as the ' art of 

 making money,' and consequently is an emi- 

 nently practical subject. A treatise therefore 

 should be devoted mainly to modern methods, 

 subordinating historical descriptions and data, 

 a plan quite the reverse of that given by Mr. 

 Hiorns. 



Metallurgical processes are of such rapid 

 development that characteristic factors of any 

 one time often become obsolete in a decade, and 

 a work bearing the date of 1895 should present 

 the methods brought up to at least within a few 

 years. The present work quite fails in this re- 

 spect also. Many errors have been perpetuated 

 from previous works, and a number of illustra- 

 tions are given of furnaces which have not 

 been used for twenty years and more. Ameri- 

 can practice is painfully weak, and since we are 

 the greatest individual producer of silver, gold, 

 lead, iron, copper, zinc and mercury, this criti- 

 cism is of great weight. Some glaring errors in 

 this respect are as follows: 



Under blast furnace practice for pig iron the 

 furnaces quoted as embodying modern ideas 

 are not water-cooled and they have exterior 

 fore hearths. In view of the magnificent prac- 

 tice at the Edgar Thompson works where, two 

 years ago a single furnace produced over six 

 hundred tons of cast iron in twenty -four hours, 

 the type of furnace as given by Mr. Hiorns is 

 decidedly ancient. 



Under the metallurgy of lead the shaft fur- 

 naces given are all of the old type ; not one of 

 them is water-cooled. Under zinc the English 

 method is quoted as in use, a^hough Dr. Percy 

 remarked in a lecture that years ago he sought 

 'for evidence of this process, but failed to find 

 even the ruins of the furnace foundations. 

 Under steel the American modifications of 

 rapid blowing and low silicon irons are entirely 

 ignored, etc. 



