43 



Mr. Ingpen said it was evidently a very favourable specimen of the solar 

 microscope, but in its present condition it was of course unsuited for other 

 purposes ; probably, however, it would be found that the optical portion was 

 made to detach so that it might be adapted for use in the ordinary way. 



The President, in proposing a vote of thanks to Mr. Epps, expressed his 

 feeling that however interested they might be in what had been so well 

 done so long ago, they might congratulate themselves upon the greater 

 capabilities of the microscopes in use at the present time. 



Mr. J. W. Groves exhibited a freezing microtome, which he described as 

 an improvement upon the one which he had exhibited at the April meeting 

 of the Club. The arrangement for freezing by means of ether spray re- 

 mained practically the same, but the apparatus was fitted so as to be clamped 

 to the table, and was provided with a sliding tube which made it available 

 for use with substances which required to be embedded in wax. This holder 

 was raised as required by a divided micrometer screw ; the razor was also 

 fitted into an improved frame, so constructed that it could be worked readily 

 in any direction, whilst the inclination of the edge of the blade to the ob- 

 ject could be regulated as required; the frame in which the razor was 

 clamped was fitted so as to move in a true plane on the face of the two 

 steel runners fixed on either side of the stage. The arrangement was 

 further described by means of drawings on the black-board. 



The President thought the apparatus was very beautifully made and con- 

 trived. He inquired whether it took long to freeze objects in that way, 

 and what amount of danger attended the use of such an apparatus at 

 night in proximity to a light ? 



Mr. Groves, in reply, said he had on the former occasion, when he exhibited 

 the apparatus, explained that there could be no danger in using the appa- 

 ratus, because a tube was provided which carried the whole of the 

 waste ether into the open air through a window or otherwise. He also 

 then showed that if the bellows provided were not sufficiently powerful 

 the spray could be driven by means of a contrivance worked by the foot or 

 by any other motor. He could perfectly freeze a specimen in If minutes, 

 and that with the cheapest methylated ether at sp. gr. 73. 



Mr. J. W. Reed inquired if the machine could be used with ice and salt, 

 as he thought that freezing with ether would be inconvenient in private 

 houses and in some places it might be difficult to obtain. 



Mr. Groves said this machine could not be used with ice and salt ; the old 

 form of it was so used, but this improvement had been made as rendering 

 the process far more convenient. The only inconvenience likely to arise 

 was from the escape of the ether vapour into the house, but only a very 

 small quantity was likely to do so during the act of filling the reservoir. 

 The objection, on the other hand, to ice and salt was that in most parts of 

 the country ice was difficult to procure at any reasonable price, and in many 

 places it could not be had at all, whilst ether could be carried and kept any. 

 where, and was always ready for use. As regarded the comparative ex- 

 pense of the two methods, he thought the cost of the ether was about the 

 same as that of the ice without the salt. The old machine could be 



