212 THE MICROSCOPICAL NEWS. 
the potash, and the condition of the diatoms. I can lay down no 
positive rule regarding this, but can only recommend the ex- 
perimenter to try again when he fails in the first essay.”—See 
J.R.M_S., June, 1883. 
THE METHODS OF PREPARATION.—Both organic and inorganic 
matters require special methods for their preparation as a means of 
study. Thus, the processes of pulverisation, levigation, of slitting, 
and of grinding minerals and rocks, are beset with difficulties of 
detail, which, for want of suitable attention, prove to be insur- 
mountable barriers to the tyro, whereas their observance but shows 
that he has made a ‘‘ mountain of a mole-hill.” So, also, the im- 
pediments to successful section-cutting, staining, and mounting are 
all traceable to a neglect of minute particulars, such as the wetting 
of the edge of the razor with spirit, the practice of drying the edge 
of the blade when it is set down for a few minutes, the use of a 
mordant previous to staining certain vegetable tissues, or the 
thorough dehydration of sections before they are mounted in 
Canada balsam or dammar solution. 
In the opening pages of his work on the microscope, Beale 
makes the following observations: ‘‘ Manual dexterity, although 
subordinate to many higher mental qualifications, is as essential for 
the successful prosecution of microscopic observation as it is for 
that of every kind of experimental science. It assists us in the 
discovery of new means of enquiry and in devising methods by 
which difficulties may be surmounted. Without skilful manipula- 
tion we can neither teach by demonstration facts which have been 
already discovered, nor hope to extend the limits of observation 
and experimental knowledge. It is not, therefore, surprising that 
many of the most important facts which have been recently added 
to microscopical science, have been discovered by men who had 
previously well-trained themselves in experiment—particularly in 
practical chemistry and minute anatomical dissection. Improve- 
ments in the practical details of manipulation almost necessarily 
precede an advance in natural knowledge, and invariably promote 
and expedite true scientific progress.” 
But although manipulative skill is a very necessary adjunct to 
microscopical research, an attainment of the understanding of the 
general principles of action at the outset, sometimes proves to be 
the most arduous portion of the work, and very often is the only 
impediment to success. Practice and perseverance, brought to bear 
upon previously gained knowledge, are the only royal roads to 
manual dexterity, and it thus becomes the duty of the instructor to 
point out, not merely what path ought to be taken, but the various 
pit-falls which everywhere surround the beaten track, and how best 
to avoid them.—/rom the Methods of Microscopical Research, ADY. 
