October 27, 1905.] 



SCIENCE. 



521 



This is a revised and enlarged edition of 

 the work first published by Professor Thorp 

 in 1898. While the earlier edition noted the 

 most important inorganic and organic indus- 

 tries, the subject of metallurgy was entirely 

 passed by because, as the author stated, in- 

 struction in it is generally given independ- 

 ently of that relating to technical chemistry. 

 In this newer edition, however, he has thought 

 it best to include an outline of elementary 

 metallurgy and this, therefore, covers 54 pages 

 and constitutes Part III. of the book. 



Thorp's ' Chemistry ' is too well known to 

 need an introduction to teachers of chemistry, 

 and its well-merited success has brought about 

 a revision that can not but help to make it 

 more generally acceptable for purposes of in- 

 struction. While it is obviously impossible 

 for any one man to write with the authority 

 of personal acquaintance with the dozens of 

 distinct industries and hundreds of special 

 manufacturing methods now in active use in 

 this country and abroad. Professor Thorp has 

 made diligent use of the literature, references 

 to which are found at the end of each section, 

 and he has, in his capacity as a teacher, made 

 numerous visits with his classes to industrial 

 plants and witnessed the actual working of 

 many chemical processes. Indeed, the evi- 

 dence of this is found so unmistakably in his 

 frequent use of workmen's factory terms, given 

 in quotation marks, that it has the effect, not 

 always to be desired, of localizing the partic- 

 ular process described. 



In general, the accounts of the individual 

 chemical industries are clearly given, accurate 

 and brought up to date. We note in this con- 

 nection the account of the sulphuric acid 

 manufacture, in which both the older chamber 

 method and the newer contact processes are 

 very satisfactorily explained and illustrated. 

 The chlorine industry also is very fully treated, 

 although some of the methods described will 

 probably only have an historical interest be- 

 fore many years with the rapid development 

 of the electrolytic methods for chlorine and 

 caustic soda, in which the chlorine is the 

 product for which sufficient utilization has to 

 be sought. These electrolytic processes, by 



the way, are also very well presented and de- 

 scribed. 



The account of the manufacture of nitric 

 acid is equally good, embodying as it does 

 recent improvements like Guttmann's and 

 Hart's and the experimental work at Niagara 

 Falls on the production of nitrogen oxides 

 from the action of high-tension electricity on 

 the atmosphere. 



We note similarly satisfactory sections on 

 the fertilizer manufacture, and mineral colors 

 or pigments, which latter is quite full and is 

 supplemented by a list of well-selected refer- 

 ences. 



With these many points of excellence it 

 may be allowed to note one or two cases in 

 which the presentation of the subject is not 

 qiiite up to the general standard. The state- 

 ment on page 41 that ' the price of the foreign 

 sulphur brought into this country is too low 

 to allow profitable working of the deposits in 

 this country ' was true a few years back, but 

 in 1904 the Union Sulphur Co. of Louisiana 

 produced 200,000 tons of a native sulphur of 

 exceptional purity and began the invasion of 

 the European markets. To prevent the seri- 

 ous crippling of the Sicilian sulphur indus- 

 try, the Anglo-Sicilian Sulphur Co. has just 

 made a compact with the American Company, 

 by which they give the latter the undisturbed 

 field of the United States and a part of 

 Europe in return for the maintenance of 

 prices. Similarly the statement of the Amer- 

 ican bromine production methods on page 

 227 is hardly an adequate picture of the 

 industry which within the last two or three 

 years has had a great development in Mich- 

 igan, in consequence of the use of electrolytic 

 methods for liberating chlorine. 



Part II., devoted to the ' Organic Industries,' 

 covers exactly the same number of pages in 

 the treatment as the Inorganic portion, and is 

 also in the main very satisfactorily dealt with. 

 This is especially true of the section on ' Ex- 

 plosives and on Textile Industries.' The same 

 is true of other sections, although in the ac- 

 count of petroleum we do not find much men- 

 tion of the radical differences in composition, 

 and consequent differences in practical value, 

 in the American petroleums, such as Pennsyl- 



