Page:Principles of Microscope.djvu/11



PREFACE

one who has to use the microscope must decide for himself the question as to whether he will do so in accordance with a system of rule of thumb, or whether he will seek to supersede this by a system of reasoned action based upon a study of his instrument and a consideration of the scientific principles of microscopical technique.

The present text-book has no message to those who are content to follow a system of rule of thumb, and to eke this out by blind trial and error.

It addresses itself to those who are dissatisfied with the results thus obtained, and who desire to master the scientific principles of microscopy, even at the price of some intellectual effort.

The general scope of this treatise is briefly as follows —

I have taken as my theme the technique of the microscope ; excluding from my purview such technique as has relation only to special branches of microscopic study, or to the employment of the supplementary apparatus which is used in association with the microscope for the purpose of counting, measuring, analysing, or photographing microscopic objects.

In correspondence with what I conceive to be a natural, and a fundamentally important, subdivision of my subject matter, I have divided my treatise into two parts.

In Part I. I treat of the development of the object or stage-picture, i.e. of the development upon the stage of the microscope of that pattern of radiant points which constitutes the original of the magnified image formed upon the retina by the microscope.

In Part II. I treat of the development of the magnified microscopic image, and of the instrumental adjustments which minister to the satisfactory development of that image.