674 . PHARMACEUTICAL BOTANY 
micrometer or indicated on a label found pasted upon it. If 
the value indicated is 0.01 mm. (1499 mm.), then each division 
of the stage micrometer scale has a value of 10 
microns; if 0.1 mm. (149 mm.), 100 microns. 
5. Multiply the number of included divi- 
sions of the stage micrometer scale by the 
value in microns given for each division and 
divide the result by the number of included 
divisions of the ocular micrometer scale. The 
Fic, 503.—Scale of quotient represents the value of each division 
cals i eR ET of the ocular micrometer scale. 
Each small space of 6. Note the optical combination (number 
actual scale has a value of ocular, objective and tube length) used and 
of 10 “tedcrons, each keep a record of it with the calculated microm- 
large space between the 
longest lines, 100 mi- Cter value. Repeat for each of the 
crons. The length of combinations. 
the entire scale is 1 mm. To measure an object by this method, 
read off the number of divisions it occupies of the ocular microm- 
eter scale, and express the result in microns by looking up the 
recorded value for the optical combination used. 
