58 JOURNAL OF THE [April, 



rosin in oil of turpentine. The oil of turpentine will be mostly 

 absorbed by the film. Thin writing or tracing paper is then 

 laid on the film, avoiding bubbles. On carefully raising this 

 paper the film will adhere, and can be lifted off the paper it lay 

 on first. A coat of the rosin is then applied to the lower side 

 of the film, and the old paper, or tracing paper put over it. It 

 is allowed to dry on the filtering paper. In case rosin should 

 blot through the paper it is removed with turpentine. Remarks 

 can be written on the covering paper, and the whole plate, or 

 temporary support, is preserved in a portfolio between filtering 

 paper, free from pressure and open to the access of air. 



In holding such a plate against the light, it is possible to see 

 at once the coarser items. For inspection under the micro- 

 scope, the plate is put between a slide and cover-glass, adding 

 oil, creosote, &c. to make the whole more transparent. ' When- 

 ever then it is desirable to mount permanently single sections, 

 or whole series of them, corresponding pieces of the provisory 

 support are cut out and immersed in the turpentine bath. The 

 rosin being dissolved, the film is separated from the covering 

 paper, and can be mounted in the regular way. On the label 

 of the slide can be marked the numbers, corresponding with the 

 numbers embedded in the film with the sections. In this way 

 it is possible to keep a large number of sections in good con- 

 dition, easily distinguishable, and always ready for permanent 

 mounting. 



PROCEEDINGS. 



Meeting of December 6th, 1889. 



The Vice-President, Mr. P. H. Dudley, in the chair. 



Thirty persons present. 



The following Commitees were appointed by the chair : 



On Annual Reception ; Walter H. Mead, Charles S. Shultz, 

 William Wale^ : 



On Nominations of Officers ; F. W. Devoe, F. W. Leggett, 

 William G. De Witt. 



Mr. L. Riederer read a Paper, entitled " Notes on enclosing 

 in collodion sections of objects, embedded in paraffin, and re- 

 garding provisory support." This Paper Mr. Riederer illustrated 



