Surgical and Microscopical Purposes. 87 



I think it must be evident that the incandescent lamp 

 must soon replace all other forms of lamps for microscopes. 

 There is very little difference between the trouble of setting 

 up and trimming the oil lamp usually employed and that of 

 filling a small battery for use, whilst the difference in the 

 quality of the light obtained would be a considerable gain to 

 the microscopist. The battery to be used is the same as for 

 the lamp for surgical purposes, and the particular form to be 

 used must be regulated according to circumstances. 



Whatever form of battery be used, it is always advisable 

 to insert an artificial resistance in the circuit, so arranged as 

 to be able, by turning a handle, to increase or diminish the 

 light. This is especially desirable when using a battery 

 which polarises easily, as at the commencement, with the 

 battery fresh, there might be a risk of breaking the carbon 

 filament, whilst, as the battery polarised, the light would 

 gradually diminish in intensity. By means of the adjustable 

 resistance the intensity of the light can be kept at a fixed 

 standard for a considerable length of time, whilst by starting 

 with a considerable resistance in circuit, and then gradually 

 reducing it, there need be no danger of injuring the lamp by 

 excess of current. Two forms of lamps are shown to-night 

 — one on a stand to replace the ordinary lamp only ; the 

 other, and smaller one, is mounted on a stand with universal 

 attachment, but, as can be readily seen, it could quite easily 

 be attached direct to the microscope. Mr. Steam suggests 

 the use of three ]amps permanently fitted to the microscope 

 stand — one above the stage, one on the sub-stage, and one 

 below for use with the polariscope ; each lamp being con- 

 trolled by a switch, could be turned off and on at pleasure. 

 This, of course, would be a very perfect and convenient 

 arrangement, but not economical ; and probably an attach- 

 ment, proposed by Mr. J. B. Payne, that can be readily fitted 

 to either the stand condenser or to various parts of the 

 stage with a small clamp, will find greater favour with 

 microscopists. 



Art. VIII. — On Germs of Blennorrhagia, 



Translated by Mr. Rudall, F.R.C.S., from an Original 

 Paper by Dr. Ecklund, of Sweden. 



[Read 10th May, 1883.] 



