June 2, 1910] 



NA TURE 



)93 



The volume is, as usual with the Ray Society's 

 publications, well printed, copiously illustrated, and, 

 thanks to the labours of Mr. Hopkinson, provided 

 with very complete lists of reference to literature, and 

 an index. 



TECHXICAL CHEMISTRY OF SUGAR AND 

 STARCH. 

 Traite complet d'Aualyse chimiqiie, appliquee aux 

 Essais industriels. By Prof. J. Post and Prof. B. 

 Neumann. Deuxieme E<iition Franijaise entiere- 

 ment refondue. Tome seconde, deuxieme fascicule. 

 (Paris : A Hermann et Fils, 1910.) Price 8 francs. 



THIS edition of Post and Neumann's work is 

 translated by MM. Pellet and Chenu from the 

 third German edition. The particular fascicule now 

 under notice deals with the chemical control of the 

 manufacture of sugars and starches. 



Beetroot sugar naturally claims the lion's share of 

 attention in a Continental book dealing with sugar, 

 and, by following the text in the case of this product, 

 a good idea of the work as a whole will be obtained. 



An outline of the process by which the sugar is 

 extracted gives the reader in a page or two a general 

 introduction to his subject. This leads to an ex- 

 haustive account of the various methods which are 

 available for determining the quantity of sugar present 

 in any solution of saccharine substances. Naturally, 

 they are well-known processes— areometric, gravi- 

 metric, polarimetric, and volumetric; but they .-Hre 

 well explained, both as regards theory and practice, 

 and illustrated with figures of the requisite apparatus. 



Coming next to the more specialised part of the 

 work, we find, to begin with, detailed instructions 

 for the testing of beetroot seed, and also specifica- 

 tions (German, Austrian, and French) of the con- 

 ditions which the seeds are required to fulfil. Next 

 follows a scheme for the analysis of the roots them- 

 selves, including full directions for those most im- 

 portant preliminary operations the sampling and pulp- 

 ing of the materials. 



Having the pulp, what, precisely, is the best method 

 of extracting the sugar from it? Much depends on 

 this, and a full discussion of the pros and cons, of 

 the various processes is entered into ; namelv, as to 

 whether water or alcohol is the best solvent, whether 

 it should be used hot or cold, and whether this or that 

 modus operandi is to be given the palm for merit. 

 Eventually the conclusion is arrived at, and supported 

 by Dr. Herzfeld " apres de longues etudes," that ex- 

 traction with cold water is in everj- way preferable to 

 the use of alcohol for the purpose. It is simpler, 

 easier, quicker, more economical, and more exact. 



The samples of roots being analysed secundum 

 artem, and the proportion of sugar duly determined, 

 we- pass to the jus de diffusion obtained in the actual 

 manufacture. This is a weak aqueous solution of 

 sugar and other soluble matter extracted from the 

 roots by diffusion in water, and full directions are 

 given for its examination. Next the syrups and 

 massecuites are dealt with, modified processes of 

 analysis being used, to suit their more highly sac- 

 charine nature; and eventually the finished products — 

 NO. 21 18, VOL. 83] 



the dry sugars and molasses — come under review. 

 This, however, is not all ; there is the question of 

 by-products to be considered, including the best 

 methods of utilising the residues from the pulp and 

 molasses; and also there is the examination of the 

 various materials, namely, water, chalk, carbonic acid, 

 sulphuric acid, strontianite, and so on, that are used 

 in the various stages of the manufacture. 



These matters are all dealt with at length. Many 

 figures of the necessary apparatus are given, and also 

 several tables of numerical values which will much 

 facilitate the analyst's work. 



The remaining sections of the book, treating of 

 cane-sugar, starch, dextrine, and glucose, are written 

 in a similar practically useful manner. If in these 

 industries, or in the future British beet-sugar pro- 

 duction to which some hopeful eyes are turning, any 

 chemist requires a laboratory handbook, he might do 

 worse than study the one under notice. C. S. 



PETROLEUM MINING AND OIL-FIELDS. 

 Petroleum Mining and Oil-field Development. A 

 Guide to the Exploration of Petroleum Lands, and 

 a Study of the Engineering Problems connected with 

 the winning of Petroleum. By A. Beeby Thompson. 

 Pp. XX + 362. (London : Crosby Lockwood and 

 Son, 1910.) Price 155. net. 



THE engineering part of the book contains a large 

 amount of instructive information, especially in 

 regard to customary procedure in Russian oil-fields, 

 but the author betrays a lack of knowledge of recent 

 practice in some of the American oil-fields. Thus, his 

 remarks on steel wire cable drilling on p. 193 are 

 misleading, for it is common knowledge that at the 

 present time this system is certainly in favour in the 

 United States, and may, in fact, be said to be gener- 

 ally used for deep wells in that country, often after a- 

 depth of 600 to 800 feet has been reached. Similarly, 

 the statement made on p. 218, as to the method 

 adopted when a dropped tool cannot be recovered by 

 "fishing," ignores the usual practice of "side-track- 

 ing " by raising the casing and drilling off with a 

 wedge. Again, on p. 238, the diameter of the last 

 string of casing is understated, for American wells, 

 started with a diameter of 12 inches or 14 inches, are 

 frequently completed at a depth of 3000 feet, or even 

 4000 feet, with a diameter of 6 inches, and it is 

 incorrect to state that in the United States the casing 

 is always manufactured from mild steel, for wrought- 

 iron casing is manufactured in that country- and is 

 readily obtainable. In the description of the process 

 of cementing wells, on pp. 266-8, there is no mention 

 of the latest and most effective sj-stem, which con- 

 sists in pumping the fluid cement, without any ad- 

 mixture of sand, through tubing packed inside the 

 casing, so that it circulates below the shoe and passes 

 up on the outside of the casing, which is afterwards 

 lowered and the packer withdrawn. 



The description of fishing tools is a good and com- 

 prehensive account of these appliances, but generally 

 the treatment of the engineering branch of the sub- 

 ject is unequal, and there is a predominance of the 

 Russian practice, to which the author unconsciously 



