330 



somewhat lower refractive index than balsam, and therefore the more trans- 

 parent portions of these objects would be easier seen when mounted in it. 

 He should like to ask the question whether any member knew a way of 

 mounting specimens in glycerine jelly without air-bubbles when no heat was 

 used ? 



Mr. Stiles said he had given some attention to the subject, and had been 

 much interested in it ; he noticed that Mr. Gilburt mentioned having used 

 chloride of soda, and he would suggest the use of hyposulphide of sodium, 

 as being better calculated to assist in the elimination of the chlorine. To 

 get rid of bubbles out of the tissue he found it quite effectual to place the 

 specimens in a little spirit and water — one part of alcohol to three parts of 

 water — and then put them under the air-pump for about an hour. As an 

 improvement upon oil of cloves, he had used oil of cajeput, and found that 

 it produced better results. He had recently obtained some of this oil which 

 had been redistilled, and was purer and lighter in colour than that ordi- 

 narily sold. Oil of cajeput had also the advantage of being cheaper than 

 oil of cloves. In addition to the magenta and blue dyes he had also used a 

 mixture of picric acid and carmine, and found that the picric acid attacked 

 the woody fibre, and that the carmine became associated with the pith and 

 the bark. No heat should be applied whilst mounting. 



Mr. Ingpen thought the advantage of glycerine jelly was that it could 

 be used without a cell ; there was a further advantage that an aqueous 

 solution of the dyes could be used if desired, in which case the tissues were 

 less liable to undergo distortion. In using the jelly very little heat was 

 sufficient, for when once melted it could be used with a heat not much 

 exceeding that of the hand. 



Dr. Matthews mentioned, as a caution, that invariably on the mixture of 

 alcohol with other fluids, there was an extrication of air-bubbles. If the 

 specimens were first put into water and then into glycerine jelly this diffi- 

 culty would not arise. 



Mr James Smith said that a mixture of half glycerine and half picked 

 gum arabic in water was a very good medium ; it was beautifully clear and 

 answered the purpose admirably. 



Mr. Sigsworth recommended also a mixture of glycerine and camphor- 

 water. 



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

 the opinion that the very practical paper which he had read would be of 

 great use to the Club. 



A vote of thanks to Mr. Gilburt was unanimously carried. 



The Secretary reminded the members that at the next ordinary meeting 

 nominations of gentlemen to fill four vacancies on the Committee would 

 have to be made. The nominations of President and Vice-Presidents would 

 also be made then, as that would be the meeting previous to the Annual 

 Meeting in July. 



Notices of Meetings and Excursions for the ensuing month were then 

 made, and the proceedings terminate^ as usual with a conversaziune, at 

 which the following objects were exhibited : — 



