December 2, 1922] 



NA TURE 



727 



ductory discourse to a course of instruction on the 

 technique of chemical manufacture. 



(2) In his little work on materials of construction 

 Mr. Griffiths deals with facts rather than with principles. 

 In his introduction he speaks somewhat contemptu- 

 ously of the designing engineer who has but little 

 knowledge of chemistry, and of the research chemist 

 who is ignorant of even the most elementary principles 

 of mechanics, both of whom know little or nothing 

 of the behaviour of materials of construction towards 

 the action of chemical substances under the special 

 conditions of the manufacture, but who are yet 

 called upon, one to design and the other to work 

 the plant. 



There is no doubt that in too many cases the 

 strictures are well merited. So long as chemical 

 manufacture is confined, as in the case of so-called 

 " heavy chemicals," to comparatively few substances 

 and those of a restricted class, the disastrous results, 

 material and financial, of such ignorance are not likely 

 to be very serious. But as the range of his work 

 extends, the chemist is called upon to face an increas- 

 ing complexity of conditions in manufacture, and he 

 cannot be too well informed concerning the application 

 of constructional materials to chemical plant : he must 

 know, not only the usual influences of atmospheric 

 action, weathering, rusting, etc., but also the effects 

 of physical conditions and the specific action of sub- 

 stances in varying circumstances of temperature, pres- 

 sure, catalytic influences, etc. 



In the space of some six or eight short chapters 

 the author deals with the properties of bricks 

 and tiles, refractories ; stone, natural and artificial ; 

 ceramic materials and glass ; rubber, ebonite, leather 

 etc., wood ; and a variety of non-metallic materials, 

 such as mortar, cement, lutes and jointings, paints 

 and enamels. In the very limited space allowed to 

 the author, the treatment is necessarily highly con- 

 densed, but it gives the essential facts accurately and 

 in sufficient detail. 



(3) The little book on " The Weighing and Measuring 

 of Chemical Substances," by -Messrs. Malan and Robin- 

 son, is concerned solely with these operations as they 

 may, or should be, carried out in chemical works. It 

 deals with the general mechanical principles and 

 theoretical considerations applicable to the various 

 types of instruments employed. These, of course, 

 differ according to the physical nature of the substance 

 to be weighed or measured, i.e. whether solid, liquid, 

 or gaseous. All the commoner forms of apparatus 

 are referred to, as well as those of modern type, some 

 of which are of rather elaborate construction and need 

 intelligent use. The booklet may be commended as a 

 useful account of methods to be employed in checking 

 NO. 2770, VOL. I 10] 



tin various stages of the production of a manufactured 

 article with the view of economy and the prevention 

 of waste. 



(4. 5) The two books by Mr. Norman Swindinon the 

 flow of liquid chemicals in pipes and chemical works 

 pumping are concerned with associated subjects of 

 great importance to the chemical engineer. In the 

 first-named the general principles involved in the con- 

 sideration of viscous flow — kinematic and absolute 

 viscosity, the relation between mean velocity and 

 velocity at axis of pipes, the practical application of 

 the kinematic viscosity equation, the flow of liquids 

 in channels, and pipe-line losses — are set out in such 

 detail as the very limited space at the author's disposal 

 permits. 



Justice is done to the classical work of Osborne 

 Reynolds and to the more recent investigations 

 at the National Physical Laboratory by Dr. Stanton, 

 and of Mr. E. Parry of the English Electric Company. 

 In the discussion of the various formulae for expressing 

 the relation between viscosity and temperature, 

 Rodger, the collaborator of Thorpe in their investiga- 

 tion of the connexion between viscosity and chemical 

 constitution, is inadvertently spelt Rogers. The book 

 concludes with a number of useful tables showing the 

 viscosities at different temperatures and the densities 

 of various liquids of importance in the chemical 

 arts. 



The booklet on pumping contains a description of 

 the construction and mode of working of pumps em- 

 ploved in connexion with corrosive liquids — a problem 

 of a very different order of difficulty compared with 

 that with which the hydraulic engineer has usually to 

 contend. The various types of pumps applicable to 

 the conditions in chemical works are succinctly 

 described with the aid of suitable figures and diagrams. 

 Both books are useful compilations, and will be of 

 service to the works manager and chemical engineer. 



(6) Dr. Schidrowitz's little book on " Recent Pro- 

 gress in Rubber Chemistry and Technology " is a work 

 of a very different order, and is in no wise connected 

 with the Chemical Engineering Library. It deals 

 more particularly with the extraordinary development 

 of our knowledge concerning the nature of rubber, 

 especially of plantation rubber, the conditions of its 

 economical production, the mechanics of vulcanisation, 

 the properties of vulcanised rubber, and the technique 

 of rubber manufacturing processes — a development 

 largely due to the creation of the tyre industry. Dr. 

 Schidrowitz is an acknowledged authority on the subject 

 of his book, and it is certain, therefore, to command 

 the attention of all who are interested in rubber, 

 whether as producers or as manufacturers. It is 

 significant how little is heard to-day of synthetic 



