690 



NATURE 



[January 27, 192 1 



ai the author remarks, " who had more enthusiasm 

 than knowledge." It may now be said to be 

 firmly established, thanks largely to the magnifi- 

 cent work carried out in the experimental stations 

 of the United States Department of Agriculture. 

 Prof. Harris has produced a compact and useful 

 treatise on a subject which is of the greatest in- 

 terest to us in the United Kingdom, and also to 

 those in other parts of the Empire where the beet- 

 root might be cultivated. The manufacture of 

 sugar from beet presents numerous difficulties, 

 and all who are interested in the subject would do 

 well to study the present little volume. The text 

 is clearly written, and the information it gives is 

 concise and complete. A valuable feature is the 

 list of books, periodicals, bulletins, and reports, 

 in the English language, which is appended. 



(2) Most teachers of specific branches of science 

 prefer to write a book for the guidance of students 

 in which the subject-matter is arranged in that 

 particular manner and sequence to which they 

 give preference. The book before us is one of 

 that class. It is written by a sugar expert for 

 the guidance of his students. We believe that 

 Mr. Heriot is the only lecturer in Great Britain 

 on sugar technology — a subject of such vast im- 

 {jortance to the British Empire. The reviewer is 

 the chairman of the Empire Sugar Supply (Tech- 

 nical) Committee, which issued a preliminary 

 report in July, 1919. Information had been ob- 

 tained from the Dominions, Dependencies, 

 Colonies, and Protectorates of the Empire show- 

 ing to date the production and consumption of 

 sugar in the Empire, and the possibilities of in- 

 creasing the production to such an extent as to 

 render the Empire self-supporting as regards this 

 commodity were considered. The report has been 

 sent to members of the Government and to numer- 

 ous other Members of Parliament and high 

 officials. Up to the present, however, the only 

 movement on the part of the Government has 

 been the appointment of a committee of experts 

 to visit India and report on the possibilities of 

 extending sugar production in that part of the 

 Empire. 



The appearance of Mr. Heriot 's book is a 

 welcome sign that the teaching of sugar tech- 

 nology within the United Kingdom is now pro- 

 gressing. The problem of Empire sugar needs 

 a sufficiency of trained scientific experts, for the 

 industry is no longer one that can be left in the 

 hands of rule-of-thumb workers. Its principles 

 require a knowledge of agriculture, botany, 

 chemistry, and engineering, which can only be 

 gained at an iiistitution such as that w-ith which 

 Mr. Heriot is connected. 



The text of the book is divided into ten 

 NO. 2674, VOL. 106] 



parts, covering well the whole field included 

 under the title, whilst the numerous illus- 

 trations add much to its value. The first 

 five chapters, dealing with scientific princi- 

 ples, cover but thirty-two pages, and they 

 should certainly be extended in future editions. 

 They are, by reason of their brevity, dogmatic 

 rather than educational, and as an instance the 

 opening chapter on the formation of sugar by 

 plants may be cited. Nothing is said of plant 

 respiration, whilst in the converse phenomenon, 

 photosynthesis, formaldehyde is given as the first 

 product. It is stated, without authority, that 

 formaldehyde has been detected in minute quan- 

 tities in the leaves of plants, but reference should 

 have been made to a paper by Jorgensen and 

 Kidd in 1917 in which it is shown that form- 

 aldehyde arises from chlorophyll in the absence of 

 carbon dioxide. 



Although a detailed description of analytical 

 methods would be out of place in the present 

 volume, chap, xv., covering twelve pages, is 

 meagre — so much so as to make it of no value 

 whatever. Under "reducing sugars," for ex- 

 ample, the following may be quoted from the text : 

 "A measured volume of Barreswill's (Fehling's) 

 solution is diluted with water and boiled. The 

 juice is then gradually added until the whole of 

 the copper is precipitated as cuprous oxide. From 

 the volume of the juice thus added, the reducing 

 sugars per 100 of juice can be calculated." 



The main portion of the book is devoted to 

 technology, and here the matter is well chosen. 

 Mr. Heriot has certainly added a useful volume 

 to the literature of sugar manufacture, and one 

 which was needed in our Empire, since it em- 

 braces the manufacture of sugar from both cane 

 and beet. 



(3) This book is one of a series the object of 

 which is to give a "general survey" of industries 

 " showing how chemical principles have been 

 applied and have affected manufacture." "The 

 subject," says the editor, "will be treated from 

 the chemical rather than the engineering stand- 

 point." The impossibility of giving more than 

 an outline of the subject is admitted, but it is 

 hoped to stimulate greater interest in certain 

 industries to which the nation has paid insufficient 

 attention. 



Commencing with an introduction of fifteen 

 pages dealing generally with the carbohydrates, 

 cellulose, starch and its hydrolytic products, and 

 the sugars, the remainder of the text is divided 

 into six parts, each subdivided into sections. It 

 deals with starch, dextrin, glucose, maltose, cane-' 

 sugar, beet-sugar, sugar refining, minor sources 

 of sugar, caramel, malting, brewing, wine, potable 



