PROCEEDINGS OF THE SOCIETY. 161 



much more easily with light conveyed in this way, because no stray 

 light from the lamp could enter the eyes, and they had thus the great 

 advantage of working in the dark with a good light on the object. They 

 also found it very convenient to be able, from the same lamp, to furnish 

 light separately to the Microscopes of four or five students sitting round 

 a table. 



Prof. Pritchard said he had worked with a lamp of this kind three 

 or four years ago, using it successfully as a light whilst operating in 

 the ear. It looked at first very extraordinary to get light to come 

 through a rod in that manner ; but there was no difficulty in explaining 

 how it occurred ; because the light once getting into the rod was pre- 

 vented from getting out again at the sides by internal reflection. There 

 seemed some little difficulty in getting a good light, because of the 

 amount of heat from the lamp, and the necessity for a particular kind 

 of flame. The one he used was lent to him by Messrs. Ash, the dentists' 

 instrument-makers. 



Mr. Crisp said the German form of it was described and figured in 

 the Journal just published, at p. 1025. 



Mr. Karop said that on looking through the Microscope the illumi- 

 nation of the object was fairly good, but there was too little light for 

 use with any but low powers, and the arrangement entirely precluded 

 the use of the condenser. 



The President thought this was a fatal objection to it, because prac- 

 tically for all delicate work one required the condenser constantly going 

 in some form or other. 



Mr. C. L. Curties exhibited and described a new form of portable 

 Microscope, intended for the use of medical men. It consisted chiefly 

 in the folding tripod foot adapted to one of Baker's histological Micro- 

 scopes. The body-tube was of the Continental length, 9 in. closing to 

 6 in., and there was a centering substage. 



Mr. Ahrens' new erecting Microscope was exhibited. In this two 

 right-angled prisms are made use of over the objective, Mr. Ahrens 

 claiming that by this method there was less distortion than when lenses 

 were used for erecting the image (see this Journal, 1888, p. 1020). 



Mr. Crisp handed round for inspection a curious little Microscope, 

 in which he remarked that both Science and Art were combined, A 

 seated figure of a monkey held the stage and mirror in its extended 

 hands, a small brass arm screwed to the head of the figure serving to 

 carry the tube (sujpra, p. 113). 



Mr. Griffith's description of a new form of camera for microphoto- 

 graphy, consisting of a conical wire spiral covered with black cloth, was 

 laid before the meeting (see this Journal, 1888, p. 1031). 



Mr. C. L. Curties said he had tried this plan, but found the spiral 

 troublesome to close, as it had a tendency to shoot out sideways. It did 

 not offer much advantage in point of space over the portable bellows 

 camera, which, though extending to 3 ft., could be shut up to 5 in, by 

 4 in,, inclusive of the back, 



1889. M 



