APPENDIX 
451 
SYNOPSIS OF COURSE IN INTRODUCTORY CHEMICAL MICROSCOPY. 
CORNELL UNIVERSITY—DEPARTMENT OF CHEMISTRY. 
I. MICROMETRY. (See pages 180-190.) 
I. Determine the ocular micrometer scale values for each of the three objectives 
attached to the nose-piece of the microscope. Fill out in your note book the data 
called for in the following table. 
Microscope No. 
Objective. 
Tube Length. 
Number of Divs. Ocular 
Scale to equal 0. i mm. 
I Division of Ocular Scale 
equals. 
32 
n 
16 
8 
2. Thickness of Paint Films. (See page 196.) Count the number of coats of 
paint on the wooden block given you. Record their colors in the order in which 
they occur, numbering from inside out. Are they all of the same thickness? 
What are the variations in thickness if any? Do the paint films differ'in character, 
in uniformity of spreading? Assuming that there has been no shrinkage, how 
many square feet of surface will be covered by i gallon of paint number 2 (counting 
from the wood outwards) if applied to the same kind of surface? Record in your 
note book the serial number of the sample and all data. 
3. Estimation of Weight. (See page 209.) Measure at least three different 
diameters of the metal bead found in the preparation given you. Average the 
results and compute the weight of the bead. 
4. Calibration of Sieves. (See page 194.) Determine the number of meshes to 
the inch; the average diameter of the wires; the average diameter of the openings. 
Ascertain whether the meshes are uniform or variable. Calculate the diameter 
of opening and the number of meshes to the inch of the next finer sieve the diameter 
of whose openings would have to that measured a ratio equal to the square 
root of 2. 
5. Does a given powdered material conform to specifications? Consult the specifi¬ 
cations posted on the bulletin board. Spread the material in question evenly on 
an object slide. Adjust the drawing camera (,see pages 128 and 129). Draw the 
outline of the grains clearly and sharply upon a note book page. Use great care 
to sketch the particles in average areas. Remove the preparation and without 
making any other changes, slide a stage micrometer in place. Trace at the lower 
right-hand corner of the page five or more divisions of the stage micrometer. By 
means of the scale thus drawn measure the particles as sketched and ascertain 
