10 BULLETIN 898, U. S. DEPARTMENT OF AGRICULTURE. 
INSPECTION. 
On arrival at the primary market each barrel of turpentine is 
opened and inspected to determine the grade (color), purity, absence 
of water, and volume of contents. 
GRADES AND GRADING. 
The grade of ‘gacventns is determined chiefly by the color, which 
yaries from almost colorless to a decided yellow, depending on the 
age of the gum from which the turpentine was made, the season of — 
the year when the gum was collected, the care shown in its distilla- 
tion, its age, and the amount of exposure to light or air undergone 
after distillation. 
Four EO ES grades of turpentine, known as ‘‘water white,” 
‘‘standard,”’ ‘‘one shade off,” and ‘‘two shades off,” are recognized 
on the primary naval stores markets. “Standard” is the basis for 
price quotations. Turpentine which grades one shade off or two 
shades off is accepted by buyers only at a discount, and when pur- - 
chased by the large dealers is usually mixed with enough water white 
turpentine to bring the color up to standard. Turpentine which has 
a color deeper than two shades off, as defined hereafter, is not mer- 
chantabie under the naval stores market rules. 
Since the color of some turpentine changes markedly in short 
periods of time, it has so far been impossible to devise color standards 
for turpentine which consist wholly or in part of turpentine itself. 
The light color of the higher grades has made it impracticable to select 
any colored solution, either organic or mineral, which is permanent 
and fast to light, as a color standard for turpentine. For the present, 
therefore, the grade of turpentine is determined by comparison with 
a No. 1 yellow Lovibond tintometer glass. The several standards, 
defined in terms of the depth of column which will match in color 
the No. 1 yellow Lovibond glass, are as follows: 
Water white.—The eclor of a column 150 mm. in depth shall match 
a No. 1 yellow Lovibond tintometer glass. 
Standard. —The color of a column 50 mm. in depth shall ae a 
No. 1 yellow Lovibend tintometer glass. ° 
One shade off —The color of a column 25 mm. in depth shall match 
a No. 1 yellow Lovibond tintometer glass. 
Two shades off —The color of a column 15 mm. in depth shall Hite : 
a No. 1 yellow Lovibond tintometer glass. 
The color or grade is determined in the laboratory as ee on 
page 44. This procedure, however, is not practicable for routine _ 
examination of turpentine on the storage and receiving yards. For 
this purpose 4-ounce, flat and polished-bettom, oil-sample bottles are 
completely filled with turpentines which have been recently tested 
and adjusted by the laboratory method, so that the required depth 
of column to equal the No. 1 yellow Lovibond glass is exactly 150, 50, 
25, and 15 mm., respectively, and securely corked. In grading, a 
ee tr be MAS Pian 
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