102 THE NORTHERN MICROSCOPIST. 


Owen, and Mr. Nasmyth, a celebrated dentist in London, in 
studying the structure of recent teeth. And then I believe that 
Dr. Carpenter was the first to introduce the method as applied to 
the study of the structure of recent shells. 
Very little else was done for some time, and, as far as I am 
able to ascertain, nothing whatever had been done in applying the 
method to the study of sections of rocks for geological purposes. 
Curiously enough, up to some years after I introduced that 
method, the old plan of studying the structure of rocks was still 
adopted, namely, crushing portions of the rock and examining the 
powder. 
I was aware of the application of the Microscope to fossil wood 
and teeth, and it occurred to me, about thirty-three years ago, that 
a very great deal of light might be thrown on the structure of 
rocks by preparing thin sections of them, and, as I daresay many 
of you are well aware, that suggestion has borne a wonderful 
amount of valuable fruit. 
I believe that the first sections I prepared were some very 
imperfect ones from the Carboniferous Limestone of Derbyshire. 
I have not seen them for years, and the only interest attaching to 
them would be that they were the first that were prepared. 
But a short time after that I established myself at Malvern, to 
study the Geology of the Malvern Hills; and it was with specimens 
obtained here that I first began making sections of any kind of 
value for use with the Microscope, and I thought it would be 
interesting to the Members of this Society if I brought down for 
inspection one of the very first sections that were prepared for this 
purpose. And here I may say a word or two with regard to this 
form of glass. I find that glasses about 1,5, inch square are much 
better for my kind of work than the ordinary form, because you 
can have a larger piece of rock, and you can work them more 
evenly in every direction, than if you have a long narrow glass. As 
an illustration of how subjects like these are developed in a 
manner which appears amusing when looked at afterwards, I will 
describe how I was led to adopt the form and size of these objects. 
Not very long after I had begun the examination of the structure 
of rocks I grounded myself well in the optical properties of 
crystals, and made for myself a rather complicated polariscope. 
This was made out of brass tubes of various sizes, and ultimately 
there was a tolerably large top portion to enable me to put crystals 
underneath, and I had to leave a square piece at the top into 
which the glasses might fit, and then was made the right size for 
the tube I happened to use. Some of these earlier glasses were 
ground by myself and the gardener on a grinding stone used to 
sharpen the scythe. 
' The size then was determined by the accidental size of this 
