l886.] NEW-YORK MICROSCOPICAL SOCIETY. 19 



an-hydrous, mixed at a temperature of 300° F., and that it is not 

 a chemical combination but a mechanical mixture, and is readily 

 separated into its original materials. 



" This medium is unchangeable when protected from the 

 air, but when exposed to it, rapidly absorbs moisture. It is a 

 solid at ordinary temperatures, is an antiseptic, dissolves readily 

 in absolute alchohol, and would seem to be a far better medium 

 than glycerine gelatine for mounting, without the addition of 

 bromide of antimony ; and I think that Mr. Booth should 

 be thanked for suggesting so valuable an addition to the 

 list of mounting mediums. 



" Antimony bromide, which is rather an uncommon salt, gives 

 the high refractive index to this base. This salt is readily decom- 

 posed. Water is not a solvent, but separates the antimony, pre- 

 cipitating it in the form of a white powder. 



" This salt is soluble in the 50 per cent, solution of boro-glycer- 

 ide and in the proportions given. It does not crystallize on the 

 slide after mounting, but when more of the salt is used it forms 

 a most beautiful polariscope object. These crystals do not 

 form immediately, and, if found on a slide, they can be made 

 to disappear by a slight heat. 



" But with this base and this salt a compound can be made of 

 any refractive index, from that of the boro-glyceride to that of 

 the solution given by Prof. Smith, which he states upon the 

 bottle to be 1.8. Each of these solutions becomes hard upon 

 cooling. 



" Prof. Smith has used this medium for several months, and 

 there is no reason why it should not be as permanent as the 

 stannous-chloride in glycerine." 



THE LATE DR. WM. B. CARPENTER. 



The Committee appointed to draft resolutions relative to the 

 death of Dr. William B. Carpenter, reported the following : — 

 To the New- York Microscopical Society : 



Your committee respectfully submit, for your adoption, 

 the following expression of sentiment in view of the death of 

 Dr. William B. Carpenter : — 



I. The New-York Microscopical Society feel that through 

 this sad event the microscope has lost one of its greatest masters, 



