80 The President's Address. 



and partly from tlie want of parallelism in tlie approach of 

 their two blades. In the new instrument a screw motion 

 adjusts the distance between two parallel blades, so that 

 they will grasp any object from three quarters of an inch in 

 diameter to the smallest size Avhich forceps of any kind can 

 advantageously hold. Natural and artificial crystals to be 

 viewed with the polariscope or the micro-spectroscope, or 

 under the Lieberkilhn, may be mentioned as amongst the 

 objects for which this holder is especially useful. It has 

 universal motions, and may be used like the stage-forceps, or 

 attached to a separate brass frame, which is most convenient. 



I may also call attention to an apparatus contrived by Dr. 

 Strieker, for the examination of objects exposed to various 

 gases, or to an electric current, which is described in the 

 * Quart. Journ. Mic. Sci.,' p. 40. 



Mr. Curteis (of Baker's) has introduced a convenient 

 series of slide-cells, of different forms and sizes, which are 

 very handy in viewing living objects. They are hollowed 

 out of glass slides, and furnished with thin glass covers 

 attached to revolving brass buttons. They are made in sizes 

 adapted to objects like Conochilus or to elongated aquatic 

 larvse. 



The International Exhibition at Paris last year afforded 

 another opportunity of comparing microscopes made by 

 makers in different countries. As a juror at the Exhibitions 

 in the years 1851 and 1862, and as reporter at the former, 

 I had good opportunities in the examination of all the micro- 

 scopes exhibited, and doubtless, at both these times, the 

 English opticians held the first place. 



It has been reported that this was not the case at the 

 recent Exhibition, and I have been anxious to ascertain the 

 facts, as, since 1862, our makers have steadily continued to 

 improve both stands and object-glasses. I learn that there 

 was only one meeting of the jury for microscopic examination, 

 and that was in a small room with many lamps. I scarcely 

 need say that careful and minute comparison under such 

 circumstances was imj)0ssible. 



That the best continental makers have considerably im- 

 proved upon their previous efforts is generally admitted ; but 

 in no case do they appear to have reached the very high de- 

 gree of excellence attained by the best English artists. It is 

 rather in America than on the Continent that our opticians 

 have to fear rivalry; and some objectives, constructed by 

 Mr. Wales (an Englishman settled in that country), have been 

 deservedly spoken of in terms of the highest praise. 



Dr. Maddox has recently brought before our notice a 



