354 Analyses of Boohs. [June, 
of colours more or less successfully. But they make no improve- 
ments ; they never see the way to a saving of time, labour, or 
materials, or to obtaining a better result. In any unusual case, 
such as dealing with any novel materials, they are lost. The 
practice and experience, therefore, must be observant and judi- 
cious if they are to lead to a true mastery of the art. It is becom- 
ing in these days more and more necessary for every artizan, 
especially in what may be called the more scientific branches of 
manufactures, to understand what are the principles of his work; 
to know why he does this and omits that, and what are the pro- 
perties of the various agents which he has to employ. We hold 
that one of the greatest misfortunes which can happen to a 
nation is to have unobservant working men. The main object 
of the City and Guilds of London Institute is to assist in freeing 
the United Kingdom from this danger. 
The work before us possesses several features which must 
certainly commend it to the common sense of all persons capable 
of judging. The language of strictly scientific circles has not 
been indulged in, preference being given to the briefer technical 
terms used in dye, print, and colour works, such terms having 
been, as far as we see explained, for the benefit of the learner. 
After a section devoted to the principles of bleaching, Mr. 
Crookes treats at some length on the kinds of water to be selected 
for dyeing and printing, on which subject he gives very useful 
and practical directions. He then passes to a consideration of 
mordants, including those of a metallic character, the tannins, 
the oily bodies, and the albumenoids, This chapter is, indeed, 
most carefully and admirably written. 
A succeeding section giving general instructions on dyeing, 
bears also the stamp of practical thoroughness. Great emphasis 
is laid upon purity and cleanliness as regards the water, the 
vessels, the colours to be used, and the materials to be dyed. 
The cautions given as to matching off and the statement of what 
is really expected from the dyer are thoroughly sound and judi- 
cious. 
In speaking of tissue printing, Mr. Crookes calls attention to 
the importance of a scientific juxta-position of colours in the 
work produced. Neglect or want of skill in this department has, 
especially in former years, made English printed goods appear at 
a disadvantage as compared, e.g., with the products of Alsace. 
He remarks : “ Colours, in themselves excellent, may be made 
to look dull, flat, and ordinary, if grouped together in disregard of 
optical laws. On the other hand, shades which, taken singly, 
possess little merit, may by judicious arrangement raise and 
relieve each other so as to produce a very fine general effect. 
Hence tissue printing stands on the very boundary line between 
manufactures and the fine arts, and requires the co-operation of 
the colour-chemist, the mechanician, and the artist. Indeed the 
ideal manager of a print-works should combine in himself the 
knowledge and the resources of all the three.” 
