PROCEEDINGS OF THE SOCIETY. 397 



MEETING 



Held on the 17th of May, 1905, at 20 Hanover Square, "W., 

 Dr. D. H. Scott, Esq., F.R.S., etc., President, in the Chair. 



The Minutes of the Meeting of the 19th of April, 1905, were read 

 and confirmed, and were signed by the President. 



The List of Donations to the Society since the last Meeting (exclu- 

 sive of exchanges and reprints) was read, and the thanks of the Meeting 

 were voted to the donors. 



From 

 [ Mr. J. E. Hasehcnod 



An Old Microscope, by Nathaniel Adams < per 



I Mr C. Jjees Curties 

 24 Micro Slides Mr. W. Mountier Bale 



Mr. C. F. Rousselet gave a description of an Old Microscope of the 

 Culpeper-Scarlet type, made by Nathaniel Adams, date about 1740, 

 presented to the Society by Mr. J. E. Haselwood, through Mr. Charles 

 Lees Curties, and differing from others of the period by having four 

 brass legs instead of the usual three — on which account it was regarded 

 as a very interesting addition to the Society's collection. 



Mr. Rousselet also described a " Lucernal " Microscope, exhibited in 

 the room, and presented to the Society by Colonel Tupman. This 

 instrument — made by W. and S. Jones — had its various parts mounted 

 on a long board, the eye-piece consisting of a lens about 5 inches in 

 diameter, mounted at the end of a pyramidal wooden box forming the 

 body of the Microscope. The arrangement gave a very fair image when 

 seen through a rins; fixed at a distance of about 1-t in. from the eve- 

 lens, but it was obviously a very inconvenient instrument to adjust 

 and use. 



Mr. D. D. Jackson's paper, " On the Movements of Diatoms and 

 other Microscopic Plants," was read by the Secretary. 



The President said it was evident that they had in this paper a 

 communication of very great interest, upon a subject which had been 

 discussed ever since these organisms had been known. He did not 

 think, however, that the author had mentioned all the theories which 

 had been put forward to account for these movements. It had been 

 suggested by Max Schultze that they were due to a kind of amoeboid 

 motion of the protoplasm on the exterior of the diatom, by which it 

 was moved along the surface of any body with which it was in contact, 

 but it had since been found that diatoms also moved when quite free. 

 Otto Miiller also referred the motion to currents of protoplasm, but 

 found that they had a curved screw-like course — a reacting on the 

 surrounding water. He worked out the theory with great elaboration. 



