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from contact -with the glycerine by the elastic varnish under it. Glycerine 

 would do no harm to gold size when it could not get at it. 



Mr. Henry Lee inquired if he understood rightly that Mr. Suffolk first sealed 

 down his cells with gold size ? 



Mr. Suffolk replied that they were closed with the varnish which he allowed 

 to run under by capillary attraction. 



Dr. Matthews said he had not found it necessary to use diluted glycerine, 

 although he had successfully employed a solution of carbolic acid and camphor 

 in glycerine. The best solution for closing the cells he believed was one of gum 

 dammar in benzole diluted with gold size ; this seemed to be quite impervious 

 to glycerine even undiluted. 



The President asked what length of time Dr. Matthews had used this ? 



Dr. Matthews said he had used it about a year. He was not sure that the 

 presence of an air bubble in a cell was an evil, so long as it did not interfere 

 with a view of the object, because it served as a spring to counteract the pressure 

 arising from the expansion of the glycerine. Whenever in mounting he had 

 enclosed an air bubble he found that it caused no harm, and he was inclined to 

 regard it as an advantage. 



The Secretary observed that as Mr. Hislop had mounted a large quantity 

 of very excellent slides in glycerine, he hoped he would give the meeting the 

 result of his experience in the matter. 



Mr. Hislop said that his experience was that of Mr. Suffolk, for he had found 

 no difficulty in keeping in glycerine. His plan was to make a good seat for the 

 cover, first by a thick ring of gum dammar, allow this to become sticky, and 

 then put in the glycerine, lay on the cover, and then carefully wash off all 

 superfluous glycerine. When perfectly washed and dried put on two or three 

 coats of gum dammar to finish it. He had in this way mounted slides which 

 had kept well for more than two years, and he strongly recommended gum 

 dammar for the purpose. Care must be taken that the glass was perfectly 

 clean, and if this were attended to, and a good bed was made of cement on which 

 to place the cover, there would be no doubt as to the result. He had some large 

 preparations — such as a whole frog or toad passing from the tadpole condition — 

 which had been put up in this way, and they were perfectly intact, and not the 

 slightest exudation had ever been observed. 



Dr. Matthews mentioned that it was from Mr. Hislop that he derived the idea 

 of making a ring upon the slide ; in doing this it was necessary to wait before 

 putting on the cover until the gum dammar became "tacky," because if this 

 were not done it would be found that tears of dammar would run in and spoil at 

 least the appearance of the slide around the edge. If, after making the ring, 

 the slide were put aside for an hour before proceeding to mount, there would be 

 no danger of this occurrence. 



Mr. Hislop stated, in reply to a question from Mr. W; Hainworth, that the 

 gum dammar was used also as a substitute for marine glue in attaching cells to 

 slides. 



Mr. Tafe was of opinion that time and care were the chief secrets of success- 

 ful mounting. 



The Secretary suggested that as liquid glue was found to answer so well by 

 Mr. Suffolk, it would be well to try a solution of shell lac in benzole, which 

 would no doubt be found to dry off more quickly. 



Mr. Suffolk expressed a doubt as to whether shell lac was soluble in benzole. 

 He also said that as it was of the greatest importance that the slides should be 



