820 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
practice of tlie rule of three. They are not in any sense abstruse, and 
they are everywhere practical.” 
The second chapter deals with the Principles and Theory of Vision 
with the Compound Microscope, and of it Prof. Abbe, who saw the 
proofs, says, “ I find the whole . . . much more adequate to the pur- 
poses of the book than I should have been able to write it. ... I feel 
the greatest satisfaction in seeing my views represented in this book so 
intensively and extensively.” 
Dr. Dallinger has not shrunk from calling to his aid a number of 
specialists, among whom we may mention Mr. Crisp, the late Mr. Mayall, 
Mr. E. M. Nelson, Mr. W. T. Suffolk, and Dr. Sorby. Many sections 
of the book have been rewritten, nineteen new plates have been prepared, 
as well as 300 additional woodcuts, for many of which the editor returns 
his thanks to the officers of the Society. 
Death of Mr. Walter H. Bulloch. — We regret to hear of the death, 
on Friday, November 6th, of Mr. Walter Hutchison Bulloch, the well- 
known optician of Chicago. The deceased was a prominent member of 
the Chicago Academy of Sciences and the local Microscopical Society. 
He joined the Boyal Microscopical Society in 1882. 
Universal Microscopic Exhibition at Antwerp.* — The following 
particulars are obtained from the ‘ Chemiker Zeitung ’ : — 
The “ Exposition de Microscopie Generale, de Produits Vegetaux et 
d’ Horticulture ” has just come to an end. It was projected by Dr. 
Henri van Heurck, Director of the Antwerp Botanical Garden, a micro- 
scopist of reputation. The plan of the promoters allowed of a strange 
mixture of products. Thus, along with brewed drinks, “ schuaps ” of all 
kinds (i. e. inferior liquors), were to be found pianos, mineral oils, 
guano, and other manures. 
J. D. Moller, of Wedel, in Holstein, exhibited a collection of diatoms, 
including not fewer than 4026 distinct forms. Not only photographs of 
these species were on view, but the original specimens could be examined 
under a number of Microscopes. 
The firm of Lumiere & Collar, of Lyon, exhibited coloured 
transparent figures of microbes, just as they appear to the eye under the 
M icroscope. 
Along with Microscopes there were exhibited ovens for the cultiva- 
tion of bacteria, apparatus for sterilizing, &c. 
Among the exhibitors of instruments, a prominent place belongs to 
the establishment of Carl Zeiss of Jena. Their display included a 
selection of Microscopes, from the simplest to the most complex, com- 
bined with appliances for photographic projection, a set showing all the 
single parts of which a perfect Microscope is composed, and a collection 
illustrating the production of lenses from the crude glass through every 
stage of grinding. 
Watson & Sons, of Holborn, exhibited a large selection of Micro- 
scopes for various purposes, especially an instrument made according to 
the indications of Dr. van Heurck, adapted for delicate researches and 
for photomicrography. 
M. Nachet, of Paris, displayed instruments for research, general, 
scientific, and technical. 
* Chemical News, Ixiv. (1891) p. 169. 
