6 9 S SCIENCE PROGRESS 



carbohydrates and proteins ; certain of the earlier preparations are indicated as 

 fitted to give them the necessary preliminary practice. For the training of physio- 

 logical chemists this part of the book can hardly ibe considered to be as well 

 suited to English conditions as the courses suggested by Dr. Aders Plimmer and 

 in use at University College, London. 



An interesting glimpse of that devotion to the organisation of the minutest 

 detail, which is so characteristic of the Germans, is afforded by the Introduction, 

 which contains a long list of precautions necessary to prevent accidents. 



The list of preparations is extensive and sufficiently diversified to give ex- 

 perience in the customary methods. The methods are described in that crisp 

 and clear style so characteristic of Prof. Fischer's own papers. The original 

 literature bearing on the subject is often referred to but no attempt is made in 

 the text to deal with the theory of the interactions described. 



The translation seems well done, though it is inaccurate in places. Thus the 

 rendering of " Steinnuss " by " Brazil nut " on page 139 is calculated to deceive the 

 reader. Very objectionable is the abbreviation of litre to " li " ! It would be better 

 if the nomenclature adopted by the Chemical Society were followed throughout. 



E. F. A. 



Crystalline Structure and Chemical Constitution. By A. E. H. Tutton, 

 D.SC, F.R.S., A.R.C.Sc. (Lond.) [Pp. viii + 204.] (London: Macmillan 

 & Co., Ltd., 1910. Price 5-r. net.) 



This is the first of a series of manuals in which a number of scientific workers 

 will describe their own researches in special branches of science. The present 

 volume gives an interesting description of Dr. Tutton's classical investigations on 

 the relations of certain salts of the three alkali metals, potassium, rubidium, and 

 caesium, which resemble each other so closely in their chemical properties, and of 

 ammonium and thallium, which are less nearly allied. The compounds studied 

 were the orthorhombic simple sulphates and selenates, and the monoclinic hydrated 

 double sulphates and selenates with zinc, magnesium, or other dyad metals. 

 Those who have already read a brief account of the work which appeared in an 

 article in the first number of Science Progress (July 1906) will welcome the 

 opportunity of studying the subject in more detail. The results obtained after 

 twenty years of patient application, in which all the most advanced methods of 

 research were utilised, are full of scientific interest. Though confirming in many 

 respects the theories of Barlow and Pope, they show that the " packing " which 

 the latter assume in the building up of crystal structure cannot be of a very close 

 description, as it admits of the substitution of the five atoms of ammonium for one 

 of rubidium with very little modification of the form or even of the dimensions of 

 the space-lattice of the crystal structure. 



The variations in the crystallographic form of these compounds when rubidium, 

 caesium, ammonium or thallium are substituted in turn for potassium, or selenium 

 for sulphur, are illustrated by detailed tables of the changes in the angles between 

 the principal faces, and in the parameters and (in the monoclinic form) the 

 angle 0. The most interesting feature disclosed by these relations is the possi- 

 bility they hold out of ascertaining the spatial relations of the atoms of the 

 different elements in the space-lattice. It may be suggested that such changes in 

 shape would be more easy to realise from tables showing the variations in azimuth 

 and polar distance of the normals to the faces, referred to the horizontal plane 

 in the orthorhombic and the plane of symmetry in the monoclinic system, and in 



