264 DR, BEALE, ON THE MICROSCOPE. 
those who are students of the microscope in England; and in 
this volume on ‘ How to Work the Microscope’ we have the 
master sitting down to instruct the humblest labourer in the 
field of microscopic investigation. Nor has he spared any 
pains in striving to make his work useful to those who are 
beginning to use the microscope, for he says in his preface— 
“No work can be higher or more useful than that of assisting 
to make men original thinkers in any department of science, 
and of encouraging original work. Working books by work- 
ing men will do far more towards those ends than the most 
brilliant discoveries; and the author believes that working 
men cannot labour more usefully than by endeavouring to 
make others work.” ‘This is a noble aim, and worthy a great 
teacher. We wish we could see men of science more gene- 
rally impressed with the fact that their labour is useless un- 
less it benefits others, and that the great end of all scientific 
research should be the elevation of our common humanity by 
the widest possible extension of a knowledge of its discoveries. 
We shall not attempt to criticise the details of a work 
which, in the course of a few years, has passed into a third 
edition. Our readers, however, ought to know what improve- 
ments have been made in the present edition. In his preface 
he refers to the fact that, since the publication of the first 
edition of this work, Messrs. Powell and Lealand have suc- 
ceeded in making, at his request, an object-glass magnifying 
1800 diameters. He also expresses a hope, which has since 
been realised, that he shall receive from the same makers a 
power as much superior to this th as that is to the old +,th. 
In the subsequent parts of his work the author joins issue 
with those who think that nothing is gained by the use of 
such high powers; and he has shown by his own researches 
that, with careful manipulation, results as accurate and as 
fully to be relied on may be obtained by ;;th as by 3th of an 
inch, and that a new world is revealed to those employing the 
high powers, which is hidden from those who employ the 
lower. 
The new matter added to the present edition is more than 
twice the amount of the original edition. The author has still 
further improved upon the method of injecting and preserving 
tissues originally recommended by himself, and adopted with 
success by so many recent observers. In this edition the 
details of his method of preparing and examining tissues are 
given, and for the first time made public. 
A new feature also of this edition is a chapter on taking 
photographs of microscopic objects. This chapter has been 
revised by Dr. Maddox, to whom microscopists owe so much 
