1886.] 



MICROSCOPICAL JOURNAL. 



59 



Taking ten inches as the distance of 

 distinct vision, the magnifying power of 

 the lens,/= 1.96, is 6.1. 



The companion eye-piece varies a httle 

 in all the above measures from this one 

 and its focal length is some .02 or .03 less, 

 say 1.93. 



As a test of the correctness of the above 

 calculated power of the eye-piece, 1 meas- 

 ured the power of a Beck's ^3 with the 

 eye-piece, using a camera lucida 10 inches 

 from the axis of the tube to the paper, and 

 found it to be 71 or 72 times. Using the 

 formula of Prof. Abbe, as given in the 

 Joiirn. R. Micr. Soc. by Mr. Frank Crisp, 

 and in this Journal, vol. v, p. 21, I find 

 the ' optical tube length ' was 8.7 inches 

 and the power between 68 and 69 times. 

 Lewis H. Noe. 



[We have received a communication 

 from Mr. Bulloch discussing this subject 

 from his own point of view, which we are 

 obliged to hold over until next month. — 

 Ed.] 



MICROSCOPICAL SOCIETIES. 



Washington, D. C. 



At the 39th meeting, February 9th, Mr. 

 J. S. Diller made a communication on 

 the Microscopical Study of Rocks, an 

 abstract of which is published on another 

 page. 



In response to a question by Mr. Hitch- 

 cock, the speaker stated that he had 

 never made sections of anthracite. 



Prof. Seaman said that in his opinion the 

 use of polarized light was of as much value 

 in organic as in inorganic microscopy, 

 and cited the use of this agent in differ- 

 entiating starches, and in detecting the 

 presence of horn, teeth, etc. He related 

 an instance where he had been asked to 

 examine a piece of pillow-ticking which 

 it was supposed had been in use so long 

 that the feathers had become incorporated 

 with the cloth. The use of polarized 

 light enabled him to distinguish the 

 threads of cotton from those of the 

 feather fibre, and upon investigation it 

 was found that the cloth had been woven 

 of a thread composed of mixed fibres of 

 cotton and feathers. Shortly after, he 

 had seen a notice that this kind of cloth 

 was being made in Paris as an entirely 

 new product. 



Ur. Caldwell called attention to the use 

 of polarized light by Prof. Taylor in dis- 

 tinguishing genuine butter from its imita- 

 tions. 



Dr. Schaeffer said that he had been 

 told by a former president of the Erie 

 railroad, that the microscope was of the 

 greatest assistance in the laboratory op- 

 erated in connection with that road, in 

 determining the value of the various 

 deposits of rock along the line. 



At the 40th meeting, February 27th, Dr. 



E. P. Howland gave a short talk on polar- 

 ized light, illustrating his theme by nu- 

 merous pieces of apparatus. He also 

 showed a new projecting microscope, 

 arranged for him by Queen & Co., having 

 the lens combination beyond the focus 

 and accompanied by an amplifier. 



Mr. Hitchcock showed specimens of 

 Palme Ha ( Tet7'aspora bullosa), gathered 

 during the week, and also a mounted 

 specimen of GLgodonium Boscii showing 

 male and female filaments. 



E. A. Balloch, Seer. 



Welleslev College. 



We have a number of notices of recent 

 meetings of this flourishing Society which 

 we are unable to publish for want of 

 space — it is quite as much as we can do to 

 publish the reports of meetings as they 

 are held, so it is with regret that we must 

 set aside these interesting notices. The 

 Society was established in 1877. Meet- 

 ings are held monthly during the College 

 year. The membership varies from 25 

 to 40. The officers for 1886 are: — Miss 

 Alice Ames, President ; Miss Mary Mos- 

 man. Secretary ; Miss Lucia Clark, Cor. 

 Secretary. 



The Society has at command the hun- 

 dred and twenty microscopes belonging 

 to the College, the College library, a large 

 number of periodicals bearing on micro- 

 scopic subjects, and a collection of nearly 

 seven hundred slides. It is mostly com- 

 posed of students. Two or three lectures 

 each year are given under its auspices 

 to the whole College by distinguished 

 lecturers, and at least one exhibition. 



Buffalo Microscopical Club. 

 The programme for the current year 

 has been issued. The officers are as fol- 

 lows : — President, L. M. Kenyon, M. D.; 

 Recording Secretary and Treasurer, John 



F. Cowell ; Corresponding Secretary, Ada 

 M. Kenyon ; Advisory Council, D. S. 

 Kellicott, Geo. E. Fell, M. D., Lee H. 

 Smith, M. D. 



Regular meetings are held on the sec- 

 ond Tuesday of each month. 



Minneapolis, Minn. 

 After a brief address by the President, 

 Dr. P. L. Hatch, Mr. H. G. Carter pre- 



