23 



book case, where, of course, the members had access to them ; yet he 

 thought they might very well be laid on the table for an evening 



The President said that no doubt Mr. Smith, the Librarian, would be glad 

 to meet the wishes of the members as far as he could. 



The Secretary observed there must be a stipulation that the books should 

 not be removed from the table, specially set apart for the purpose, under any 

 circumstances. As to the slides for the Cabinet, it might be arranged that 

 Mr. Coles' slides should be left on the table for an evening, but as to other 

 specimens he thought they should be left with the Curator. 



Mr. Hailes read a communication from Dr. Whittell, written by him since 

 his return to Australia, " On making cells from thin glass," and u Hints on 

 mounting in glycerine." 



After reading the paper, Mr. Hailes remarked that he had long used a 

 similar method of forming thin glass cells, but that he used shellac instead 

 of gum. He had a few metal plates with holes of suitable sizes made in 

 them, and these plates he warmed one at a time, and fixed on the thin glass 

 with shellac. After fixing on two or three, the first rings would be cold and 

 the centre could be readily knocked out and the hole trimmed up with a 

 half-round file, then by warming the ring and slipping off the cell he had 

 very few failures. As to mounting in glycerine he had tried a plan he had 

 seen mentioned in one of the Journals a little while ago, and which seemed 

 to promise well. After wiping off as much of the surplus glycerine as could 

 be easily removed he put a ring of gum mucilage round the cover. When 

 this ring had set he dropped a little bichromate of potash upon the gum, and 

 exposed it to the action of the light. In the course of an hour the gum 

 would be converted into an insoluble resin, and the slide could be safely 

 washed in water and finished off in the usual way. He had mounted some 

 blood corpuscles of the whale in this way. and found it answered admirably, 

 but of course he could not tell how it would stand the test of time. He 

 thought the process worth trying, but it would require some years to really 

 test its permanence. 



The President remarked that any plan which required slides to be set on 

 edge, for drawing or otherwise, was objectionable. Fluid mounts should be 

 kept perfectly flat, or the object would be sure to move, especially when 

 mounted in glycerine. 



Mr. Groves said it was necessary to clear up the last trace of glycerine. 

 The most convenient method was to moisten a sable or camel hair brush 

 between the lips, and so wipe up the surplus glycerine. That answered 

 better than bibulous paper. In cementing down the covers, especially square 

 ones, it was a good plan to make a line or ring of cement on the slip a little 

 way from the cover and a similar line on the cover, and then with a brush 

 full of the cement bridge over the space between the two lines of cement. 



Mr. Ingpen inquired if the bichromate of potash was likely to be acted upon 

 by the glycerine. He feared that if the glycerine got at it, having such a 

 solvent power on salts of that kind, it might be detrimental. He observed- 

 thatthe papers just read had some extra interest in the knowledge that Dr. 



