Page 28 - My FlipBook

DENTAL MEDICINE. —
26
sieve. The following degrees of fineness will prove serviceable
in the preparation of dentifrices, polishing powders, etc. :
( Should pass through =» )
A "y^ry /7«^ powder . . , ^ sieve having 80 or more ^i\o. 00 rowuer.
-^ ^
( meshes to linear inch. )
( Should pass through a )
/- r> i
A /f«^ powder sieve having 60 meshes [=; No. DO Powder.
-' ^ (to the linear inch. 5
\ Should pass through a > - - n j
1
A moaerateiy fine powder .< sieve having 50 meshes v =;l\o. "CO rowder.
•^ -^ ' -^
{ to the linear inch. )
( Should pass through a )
r»
i
A moderately coarse powder. to the linear inch.
( )
, ( Should pass through a"|
J
A coarse pOV/aeV . . . . ^ sieve having 20 meshes ^ = I\0. 20 TOWdcr.
to the linear inch.
( )
WEIGHTS AND MEASURES.
APOTHECARIES' WEIGHT.
20 grains (gr.) make 1 scruple sc. or ^
3 scruples make i drachm dr. or z
8 drachms make i ounce oz. or 5
12 ounces make i pound lb. or tb
SCALE OF COMPARISON.
oz.
ft) dr. so. gr.
= = =
I 12 96 =r 288 5760
^ = =
1 8 24 480
= =
I 3 60
^
I 20
TROY WEIGHT.
24 grains (gr.) make i pennyweight dwt.
20 pennyweights make i ounce oz.
12 ounces make i pound ft).
3/4 grains make i carat (diamond weight) k.
SCALE OF COMPARISON.
ft) oz. dwt. gr.
= = ^
I 12 240 5760
I == 20 = 480
=
I 24
=
Ik. 3}i
AVOIRDUPOIS WEIGHT.
16 drachms (dr.) make I ounce oz.
16 ounces make i pound
ft).
25 pounds make i quarter qr.
4 quarters make I hundredweight cwt.
20 hundredweight make I ton T.
100 pounds make i central C.