342 



SCIENCE- GOSSIP. 



.W* 



MICROSCOPY 



'■ "nip I R 



CONDUCTED BY F. SHILLINGTON SCALES, F.R.M.S. 



Eoyal Microscopical Society, February 20.— 

 Mr. A. D. Michael, Vice-President, in the chair. A 

 photograph of Amplripleura prflucida, taken by 

 Mr. Brewerton, was exhibited. Mr. Nelson said the 

 photograph was interesting because it showed the 

 transverse striae as thin in comparison with the spaces 

 between them. Some optical theorists maintained 

 that the striae and spaces must be of equal width, 

 whereas he had affirmed that the striae were much 

 finer than the spaces. In many photographs of 

 this object they appeared to be of equal width, but 

 that was because the object had been baclly photo- 

 graphed. In the example before the meeting the 

 photograph had been properly taken, and therefore 

 exhibited the difference in the thickness of the 

 line and the interspaces. Mr. Eogers brought to 

 the meeting a contrivance for exhibiting a fly in 

 the act of feeding. This differed in some respects 

 from Mr, Macer's arrangement for a like purpose, 

 being a brass plate 3" x 1", underneath which a 

 brass cone was soldered to contain the fly, the plate 

 lying on the stage of the microscope like an 

 ordinary slide. Mr. E. M. Nelson read a paper on 

 the tube-length of the microscope, explaining the- 

 difference between the mechanical and optical 

 tube-length, illustrating the subject with drawings 

 and formulae. The Chairman thought there was 

 no subject connected with the technique of the 

 microscope about which ideas were more vague 

 than that of the tube-length. Many were of opinion 

 that it was the length of the brass tube, although 

 it had often been pointed out in the Society's room 

 that what was really meant was the optical tube- 

 length. The subject did not seem to be very well 

 understood. Very little practical information had 

 been published that would enable a person to 

 ascertain the tube-length of his microscope, but 

 Mr. Nelson had now given them a method by which 

 this could be found. Mr. F. W. Millett's " Keport 

 on the Recent Foraminifera of the Malay Archi- 

 pelago " was taken as read. The Chairman called 

 attention to a set of slides of Bacteria and Blood 

 Parasites exhibited by Mr. Conrad Beck. Some 

 mounted rotifers which had been sent from Natal 

 by the Hon. Thomas Kirkman were likewise 

 exhibited. 



The Quekett Microscopical Club. — We feel 

 that we shall be doing a service to our readers, 

 especially ihose resident in or near London, if we 

 call attention to the assistance they may derive 

 from membership in the Quekett Microscopical 

 Club. In this magazine (S.-G., vol. vi., p. 313), 

 quoting from the journal of the Club, we alluded 

 to the intimate connection between the Club and 

 Science-Gossip in its early days. It should be 

 understood that the Club in no way trespasses upon 

 the ground covered by, or endeavours to compete 

 with, the Royal Microscopical Society, the centre 

 of microscopy throughout the world. The Club 

 was originated, and has always existed, mainly for 



the benefit of those who take an interest in micro- 

 scopical research as a means of intelligent recrea- 

 tion ; in other words, for the encouragement of 

 the study of microscopy amongst amateurs. Several 

 of its Presidents have been eminent men of science, 

 such as Lankester, Beale, Huxley, Cobbold, Car- 

 penter, Dallinger, and others. Established in 1865, 

 it has had its home since 1890 at 20 Hanover 

 Square. The meetings are held on the first and 

 third Fridays in each month. Those on the first 

 Friday are called " Gossip " meetings, and are 

 especially helpful to beginners, being for the ex- 

 hibition of objects and for conversation. Those on 

 the third Friday are mainly devoted to the reading 

 and discussion of papers descriptive of new instru- 

 ments and the ordinary business of the Club. On 

 Saturday afternoons, during the spring, summer, 

 and autumn, excursions are arranged to well-known 

 collecting-grounds near London. These are of 

 great value to those interested in pond life, and 

 also help to promote the spirit of comradeship — a 

 special feature of the Club. An excellent journal, 

 which is reviewed in these columns, appears twice 

 a year — in April and November. This is sent free 

 to all members. The Club is in possession of 

 a valuable microscopical library as well as of a 

 cabinet comprising about 6,000 slides. The sub- 

 scription is ten shillings per annum, and there is no 

 entrance fee. The Secretary is Mr. G. C. Karop, 

 198 Holland Road, W. 



Sheffield Microscopical Society. — The 

 Transactions and Annual Report of this society 

 for the session 1899-1900 have just reached us. 

 The report shows a membership - amounting to 

 158, being a slight increase on the previous year ; 

 also a satisfactory financial position. The Society 

 is now twenty-two years old, so has more than 

 attained its majority. During the past year there 

 have been twelve fortnightly meetings, supple- 

 mented by discussion and conversation ; but we 

 note, from remarks made by the President in his 

 annual address, that the Society has apparently 

 neglected that most valuable means of sustaining 

 the interest of members and attracting new recruits 

 to microscopy, i.e. the organising of held excur- 

 sions. Amongst the papers read was one on " The 

 Bryozoa, Recent and Fossil," by Mr. G. R. Vine, 

 B.Sc. ; another on " The Adulteration of Food- 

 stuffs," by Mr. G E. Scott-Smith, F.I.C., F.C.S. ; 

 and an account by Dr. Sorby, F.R.S., of his methods 

 of preparing and preserving marine animals. This 

 is by means of an equal mixture of glycerine and 

 sea- water, in which the animals are placed for ten 

 minutes direct from the sea-water. They are then 

 transferred to water, and kept there for another ten 

 minutes to remove most of the glycerine. They thus 

 become quite limp, and can be easily arranged on the 

 slides, and allowed to dry at ordinary temperatures 

 in the open air before being finally mounted in 

 balsam. By this means the objects are not only 

 permanently preserved, but are made compara- 

 tively thin, flat, and transparent, and even the 

 natural red colour of the blood is preserved. This 

 is a great improvement upon the ordinary method 

 of preserving in alcohol or formalin, which, as we 

 ourselves have too often found, not only renders the 

 specimens opaque, but causes contraction and dis- 

 tortion. We alluded to this method in SciENCE- 

 GossiP (vol. vi., page 30). The report contains 

 portraits of Dr. Sorby ; of the founder of the Society, 

 Mr. William Jenkinson ; of the first President, 

 Mr. G. R. Vine ; and of the President for the year, 



