68 JOURNAL OF THE [April, 



49. A PIGEON-POST FILM. 



ExhiliiteJ by the. Rev. J. L. Zabriskie. 



50. SECTION OF FELTED WOOLEN GOODS. 



Exhibited by H. L. Brevoort. 



51. INSECT SCALES. 



Exhibited by C. W. McAllister. 



52. ARRANGED DIA TOMS. 



Exhibited by C. W. McAllister. 



Meeting of March 19TH, 1886. 



The President, Mr. J. L. Zabriskie, in the chair. 

 Twenty-five persons present. 



OBJECTS EXHIBITED. 



1. Graphite Scale from No. i Cast Iron: by P. H. Dudley. 



2. No. 2 Cast Iron, showing fine and coarse structure: by P. 

 H. Dudley. 



3. No. 3 Cast Iron, showing fine and coarse structure: by P. 

 H. Dudley. 



4. Vertical section of human Scalp; mounted by S. G. Shanks, 

 M.D.: by A. G. Leonard. 



5. Crow- Lice {F/iiloptenis Corvi) : by F. W. Devoe. 



6. Eggs of Chrysopa oculata, Say, /;/ situ on their long silken 

 stalks : by E. B. Southwick. 



7. Hymenopterous Insect of the genus Torymus, parasitic on 

 the gall {Rhodites bicolor) on the Swamp Rose {Rosa Carolina, 

 L.) : by J. L. Zabriskie. 



8. An Ant and one of its " cows " {aphides) : by E. B. South- 

 wick. 



9. Jaws of Larva of Nut-Weevil : by F. W. Leggett. 



structure of cast iron. 



Mr. P. H. Dudley said : " I have under the microscope a 

 scale from No. i cast iron. 



" Among the several grades of cast iron are those known as 

 No. I, No. 2, No. 3, and No. 4; special names being given to 

 other grades, as white, mottled, etc. The coarsest parts of cast 

 iron in large castings are found in the centre of the castings, 

 the apparent crystals being much larger there than in any other 

 part. No. I cast iron contains graphite, that is, it contains 



