764 peocp:edings of the society. 



with the naked eye. If the object-glass of the Microscope showing the 

 unexposed plate be racked out of focus, so that the colours are blended, 

 a very close approximation to white light is obtained. If it be placed 

 only partially out of focus, patches and channels of colour are visible — 

 due to the fact that the coloured grains are not siiificiently closely 

 intermingled. These patches of colour are what are seen in examining 

 autochrome plates, the individual grains being much too fine to be visible 

 without very high magnification. 



Mr. C. Lees Curties (C. Baker) described two inexpensive Micro- 

 scopes made by his firm. The first, known as the " Nature Study " 

 Microscope, mounted on a heavy square foot and upright both in one 

 casting, has diagonal rack-and-pinion adjustment, and sliding movement 

 to body- tube. To allow large objects to be examined, the large stage 

 (4 by 8f in.) and mirror can be removed and the specimen placed on 

 the square fiat l)ase of foot. A dividing combination objective of 

 2, 1, and |-in. powers, and one eye-piece, 28*3 mm. gauge, are supplied, 

 but the instrument is suitable for any objective up to }r in. 



The other instrument, the " Meat Examiner's " Microscope, is made 

 on the same lines, but has a stage having grooves in the vertical direc- 

 tion ; a compressor, with points to slide in these grooves, accompanies the 

 Microscope, and by sliding this in first one groove and then the next, 

 the entire surface of specimen in the compressor can be examined with- 

 out going over the same ground two or three times, as is usually the 

 case when a plain stage is used. The distance of each groove apart 

 equals the size of field of view when a 1-in. objective is employed. 



Mr. J. I. Figg exhibited a number of lantern slides — photomicro- 

 graphs from nature — showing the various stages in the growth and 

 development of fern spores, from the earliest sign of germination to the 

 mature frond, with its fructification. 



Mr. Moffatt exhibited and described a new form of filter for use with 

 agar and other media which melted at a comparatively high temperature. 

 Used in conjunction with an exhaust pump, large quantities can be 

 filtered quickly, giving a very clear filtrate. 



Mr. E. M. Nelson's description of the " Fran9ois Watkins' Micro- 

 scope " was read by Dr. Hebb. The Microscope itself, made entirely 

 of silver, was exhibited in the room, together with two from the Society's 

 collection by way of comparison. In further illustration of the sul)ject, 

 some lantern slides were shown upon the screen, representing the 

 Microscope in the different positions in which it was intended to be used. 



Mr. J. W. Gordon said that his paper, " On Mercury Globules as 

 Test Objects for the Microscope," was already in print, and had been 

 placed in the hands of Fellows of the Society who were interested in 

 the subject. He therefore thought it might be taken as read. But 

 for the benefit of those who had not seen it he gave a resume of 



