PROCEEDINGS OF THE SOCIETY. 385 



focal length of about ^, -^\, and -^ of an inch each, are placed in a 

 split cylinder at the end of the arm. When not in use the arm to which 

 the mirror is attached is folded up flat against the under surface of the 

 plate, and thus the whole apparatus can be carried in the waistcoat- 

 pocket. To use this instrument, a drop of urine containing a deposit is 

 placed on a slip of glass, and covered with a piece of mica or tliiu glass. 

 It is theu placed on the plate, on which the spring firmly retains it. 

 One of the lenses being then placed in the cylinder, the object is brought 

 into focus by means of the screw, illumination being effected by holding 

 up the instrument to the light of the clouds or a candle, or, still better, 

 by reflecting a ray of light through the object by means of the mirror. 

 If the object is very translucent, especially when epithelial cells are 

 searched for, the amount of transmitted light should be diminished by 

 means of the diaphragm. Should the deposit consist of large coarse 

 crystals, it is better placed in a little cavity ground in a plate of glass 

 (which accompanies the instrument), as they will thus escape injury 

 when covered with the piece of thin glass for examination." 



Also the following note by Mr. E. M. Nelson : — 



li It seems an excellent idea, and would, when fitted with achromatic 

 lenses in place of the Coddingtons, be most useful to diatom gatherers 

 and other searchers after small forms." 



The President said their thanks were due to Mr. Pillischer for the 

 gift of this Microscope, which would be a valuable addition to their 

 historical collection, and no doubt would be of great interest to those 

 who had given their attention to the history of the Microscope. 



Mr. C. Beck exhibited and described " Standing's Imbedding Micro- 

 tome." He also called attention to some gratings ruled by Mr. Grayson 

 of Melbourne, which had been brought from Australia by Mr. Wedeles, 

 and were exhibited in the room that evening. He thought those who 

 examined them would agree with him that they were at least equal to 

 anything which had yet been produced. The distinctness with which 

 they could be seen was largely due to the way in which they were 

 mounted, the medium employed being realgar having a refractive index 

 of 2*5. He thought it would be remembered that Mr. Nelson had 

 referred to these at their meeting in June 1898,* and also in his 

 Presidential Address in 1899,f as being the finest he had ever seen. 



Mr. Wedeles, in reply to the President, said that these rulings had 

 been so fully described by Mr. Nelson that no further explanation 

 seemed to be necessary. He might, however, mention that the bands 

 were spaced -^oVo" an< ^ * na * *he finest ruling was 120,000 to the inch. 

 Mr. Grayson had been very much engaged lately at the Melbourne 

 University, but had recently made a new machine with which he hoped 

 to do something still better. The great difficulty in the matter was to 

 get a suitable piece of diamond for the purpose. The slides which had 

 hitherto been ruled had not been made with any idea of commercial 

 profit, but entirely from scientific interest. Mr. Grayson had spent any 

 amount of time and money on this work and was now hoping to be able 

 to give some further attention to it. 



The thanks of the Meeting were unanimously voted to Mr. Beck and 

 to Mr. Wedeles. 



• This Journal, 1898, pp. 690-1. t Op. cit., 1899, p. 123. 



