564 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
tlie Cramer “ isochromatic ” plates. For developing, the following solu- 
tions (using equal parts of each) have given him clear negatives of 
sufficient contrast and graduation : — No. 1. Water 300 ; sodium sul- 
phite 25; potassium bromide 0*5; hydrochinone 1*5; methol 1-5. 
No. 2. Water 15 ; sodium carbonate 300. 
(6) Miscellaneous. 
Arc-Light Dust as an effective Abrasive Material.* — Mr. K. M. 
Cunningham has discovered, by microscopic examination, that the black 
dust which accumulates in the globes of arc lights consists to a large 
extent of opaque and translucent spherules, hard enough to polish carbo- 
rundum. He finds that this material is capable of abrading and polishing 
the hardest rocks. 
Presidential Address.f — Mr. E. Davis, in his annual address to the 
Liverpool Microscopical Society, first dealt with the suggestion that 
there is no need for a Microscopical Society at all as a separate organisa- 
tion. Mr. Davis himself, as may be supposed, does not hold this view, 
and he points out in how many various directions a Microscope gives a 
means of increasing our knowledge, and affording employment and 
delight for our leisure hours. First to be named, as they constitute a 
number of the members of a Microscopical Society, are those who 
possess a Microscope, who have neither time nor desire to make a 
systematic use of it. In the Liverpool Society an arrangement has been 
made by which experienced members give the benefit of their knowledge 
to those who wish to know how to use the Microscope. Secondly, there 
are those who endeavour to ascertain the true nature of the markings of 
a diatom or the structure of a podura scale. It is for such as these that 
opticians have continually striven to perfect lenses, and to provide 
improved illumination, and all the world of microscopy have profited 
thereby. Thirdly, there are users of the instrument who find it useful 
in their business ; while the fourth class of observers are those who use 
the Microscope for investigating the life-history or minute structure of 
vegetable or animal organisms. To them is not offered the prize of 
pecuniary recompense — their reward is the discovery of the mysteries 
of nature. Of late years a fifth class of microscopic workers has brought 
to light a class of organisms of whose importance we have as yet only an 
imperfect idea. In connection with these the President devoted the 
remainder of his discourse to an account of the life-work of Pasteur. 
Technique . % 
Microtomist’s Vade-mecum.§ — Just as we are going to press we 
receive the fourth edition of Mr. Arthur Bolles Lee’s now well-known 
work. The fact that another edition is called for three years after the 
appearance of the third edition is of itself sufficient evidence that 
Mr. Lee’s work supplies a want, but it is needless to say anything in 
* Journ. New York Micr. Soc., xii.:(1896) pp. 78-83. 
f 27th Annual Report of the Liverpool Microscopical Society, 1893, pp. 10-20. 
% This subdivision contains (1) Collecting Objects, including Culture Pro- 
cesses; (2) Preparing Objects; (3) Cutting, including Imbedding and Microtomes; 
(4) Staining and Injecting; (5) Mounting, including slides, preservative fluids, &c. ; 
(6) Miscellaneous. § London, 4th edition, 1896, xii. and 536 pp. 
