We regret to announce the death of the wife of the late John A. Long, last February, 1947 after a short ill ness. As known to diatomists all over the world, Mr. Long was one of the most skilled and generous workers.
Mrs. Caroline Booth,wife of one of our older members, the late Henry Booth - lawyer, died in late Fall of 1947. She donated microscope and outfit to our Society.
SIR HERBERT JACKSON
Sir Herbert Jackson was born March 17, 1863, and died December 10, 1936 as Emeritus Professor of Chemistry, University of London. The Professor was a most skillful microscopist and an especially fine judge of high-powered lenses.
His knowledge of chemistry, combined with his deep interest in the microscope, led him to study the production of optical glasses. As a result, he brought out a number of formula for the making of the many kinds re quired in the modern microscope and other scientific in struments.
Several new methods of illumination were also in troduced by him. For example, by the use of polarized light and dark-ground illumination,he was able to analyze quantitatively and also reproduce ceramic glazes and colored glasses found only in pre-historic and Egyptian excavations. As another example,we may mention his examination of diatoms between crossed-nicol prisms. Here he showed that a dark ground illumination was formed by the depolarization produced by the fine structures of the diatom. Likewise, by the microscopic examination of the colors produced by difraction in samples of particles thinly distributed, he was able to estimatetheir size.
His death deprived microscopy of a worker difficult to replace.
V.A.L