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instead of breathing upon the under side of the glass cover before putting it 

 over the cell, a drop of fluid were placed upon the naiddle of the cover, it would 

 be found much more effectual in preventing air bubbles from being inclosed. 

 Breathing was not always effectual, the moisture obtained in that way being 

 very evanescent; but if a drop of the preservative fluid were placed on the 

 under side of the cover so as to hang down from it, when the cover was placed 

 on the cell the drop would join with the fluid inside, and spreading over the 

 cover from the centre to the edge, would be found effectually to drive out the 

 air. He should like to know how Dr. Wood could keep the cement from 

 running in. 



Dr. Matthews was quite sure that in mounting objects of this kind attention 

 to the specific gravity of the fluid used was all important. The advantage of 

 carbolic acid over creosote was found to be great, for although creosote when 

 once thoroughly dissolved apparently afforded a very clear solution, yet after a 

 while it deposited a crust within the cell, which in many cases destroyed the 

 value of the slide ; no such thing, however, occurred when carbolic acid was 

 used. There were several modifications of different preserving fluids which could 

 be specially adapted to the substances to be preserved, and those which had 

 carbolic acid for a base were the best for algss. A saturated solution of arsenic 

 in water formed the basis of another preservative fluid, for dilution with 

 glycerine or spirit ; and a third kind of basis was camphor water, which, if 

 filtered and re-filtered through the same filtering medium would be obtained of 

 much greater strength than usual. The greatest difficulty, however, in preserv- 

 ing alg89, was in accommodating the specific gravity of the fluid to that of the 

 specimen. Another point requiring attention was the great difficulty of 

 preventing the cement from running in. Quekett found this to be a matter 

 requiring much consideration, and proposed to cut a groove or ring round the 

 object, and to put the ring of cement beyond it. His own impression was that 

 time alone would be found effectual to enable the cement thoroughly to dry, 

 and how long a time could only be taught by experience. A mixture of gum 

 dammar and gold size could be strongly recommended. If a little cement were 

 put down the side of the cell, it would cause the cement to run dowu there if 

 anywhere, rather than on the glass, 



Mr. James Smith thought that it might be worth while to try the effect of 

 immersing the objects in carbolised water before mounting them, so as to ascer- 

 tain if they would keep, and if so they could tlien be mounted. 



The President assured Mr. Smith that there was no doubt upon that point - 

 they would keep for years- but it should be remembered that when these objects 

 were obtained they were very dirty, and required cleaning. 



Mr. Hainworth asked why the objects often became of a brownish tint when 

 mounted in carbolic acid and water ? 



Dr. Matthews said this was because too much acid was used. 

 Dr. Foulerton exhibited to the meeting a bottle containing water and a speci- 

 men of Cyclops alive, which he had found in the neighbourhood of the Rocky 

 Mountains. The water was obtained by him on May 11th, at a place called 

 Green Eivers, situated at an elevation of about GOOO feet above the level of the 

 sea, and not very far from Salt Lake City. The whole country about there was 

 very flat — although called part of the Rocky Mountains — and it formed part of 

 the district known as the Alkali Plains. Every here and there along these plains 

 there were pools of water, and it occurred to him that it might be interesting to 

 know if any living thing existed in these waters, because it was most probable 



