HARDWICKE'S SCIENCE-GOSSIP. 



2CI 



On a recent visit to Oxford, living for a while in 

 college among friends who are students of the best 

 class, young men who have gained scholarships by 

 hard work, and are not satisfied with merely taking 

 B.A. and M.A. degrees, but are aiming much higher, 

 I was greatly pleased to find that the higher work 

 consisted of searching study of both ancient and 

 modern sociology and moral philosophy. These 

 students were learning to forget the brutality and 

 nastiness of the Greek and Latin poets, and replacing 

 ■such recollections by logical exercises in the subtleties 

 of Aristotle and the other Greek philosophers, and 

 •following in historical order the development of their 

 subjects by the schoolmen and modern philosophers, 

 original independent criticism of all being encouraged 

 by their teachers and examiners. This is healthy 

 •scholarship. I understand that Cambridge is moving 

 in the same direction. Sidgwick is doing noble 

 service there, if I may judge by the influence he has 

 already exerted on the high-class Cambridge students 

 I have met. 



If we must have ancient literature — old stories of 

 love and fighting — let us have those of our own race, 

 the Scandinavian Sagas. The heroes of these were 

 manly and chivalric ; their loves were comparatively 

 decent and natural. I say " if," having personally no 

 xespect for the literature of any noble savages, either 

 ancient or modern, and believing firmly that the 

 highest literature mankind has ever known is that 

 which is written in the truly classic language which 

 all mankind will eventually speak. 



DIRECT VISION MICROSCOPES. 



HAVING but few opportunies of conversation 

 with microscopists, I write with some diffi- 

 dence on a subject on which I may not have the 

 credit of being (as the saying is) "well posted ; " but 

 being in the constant and daily use of a direct-vision 

 -microscope, and observing from recent communica- 

 tions and engravings in catalogues and journals that 

 many of the old/aults and deficiencies of the instru- 

 ment remain uncorrected and unsupplied, I venture to 

 forward you an account of certain alterations which 

 1 have had made in one now before me, which have 

 -rendered it perfectly available for many purposes for 

 which it was previously inapplicable, and have made 

 it in fact, as far as my own requirements go, a very 

 •useful, instead of a nearly useless instrument. 



The faults of all the instruments of this class with 

 which I am acquainted are the following : — 



1. The object examined is rendered indistinct by 

 rthe amount of side light which falls upon it in its 

 exposed position. 



2. The stage arrangements are so imperfect that it 

 =is impossible to examine any but the central portion 

 of your slide, or, at best, such a portion as you have 

 previously arranged for examination. There is no 



possibility of hunting over the middle inch, which is 

 what the fleld-microscopist frequently wants to do.* 

 In one form, indeed, there is a brass clamp and screw 

 on one side of the rim of the orifice, and a steel 

 spring holder on the other, but though very likely 

 sufficient for class demonstration, I found it quite 

 useless for my sea-side and "green lane " purposes. 



And now for the proposed and well-tried remedies. 

 Fault No. I is easily dealt with, nothing more being 

 required than one-third of an inch of metal tube 

 blackened internally, the size of, and projecting 

 beyond, the stage aperture ; this too would easily 

 carry a polarising prism or a spot lens if desired. 



Fig. 131. — Diagram of Direct Illumination Microscope. A. 

 Brass cylinder containing wire spring which is attached to D. 

 B. Stout brass disk or stage fastened to cylinder by C— 

 A strong bar •} inch wide and Jth inch thick. D. The 

 lighter brass disk, kept in apposition to B by spring, and 

 having two rims, the one for protecting the object from pres- 

 sure, and the other for steadying purposes. E. Pin and tube, 

 also for steadying purposes. F. Brass tube blackened inside, 

 shutting offside light, etc. s, Space between B and D where 

 slide is introduced. 



Fault No. 2. The insufficiency of stage, &c, I have 

 remedied thus, the instrument on which I worked 

 being the very nice one introduced by Dr. Beale. I 

 removed the bell-shaped end entirely, and in its place 

 fixed a brass cylinder with a gap in front for the 

 use of reflected light when required, as in the 

 original arrangement. It is three-quarters of an inch 

 long and two inches wide, and to it is attached by a 

 strong bar a stout brass disk or stage with a central 



* Professor Brown's "pocket microscope" would allow of 

 some lateral examination of the middle inch of a tiny slide, but 

 the whole instrument measures only four inches long by one 

 wide, and would therefore be inapplicable for use with slides of 

 the u<ual dimensions, or for the purposes required by the field 

 naturalist. 



