42 BULLETIN 898, U. S. DEPARTMENT OF AGRICULTURE. 
which can be determined by only the intelligent and accurate use of 
the procedures described in detail on pages 43 to 48 of this bulletin. 
Large buyers of turpentine, such as paint and varnish makers, the 
several Government departments, and State and city purchasing 
agents, have for years bought turpentine on specifications which have 
been more or less specific and detailed. Rarely, however, have any 
two sets of specifications or the methods of testing of different buyers 
been identical. while too frequently the methods of testing have been 
seriously erroneous. The accompanying specifications (pp. 43-49) 
have been prepared as a guide in the purchase of turpentine, by one 
of the largest users of turpentine—the Federal Government in all its 
branches. The United States Department of Agriculture has fur- 
nished most of the data on which the specifications are based, and 
has taken the active part in formulating them. The specifications, 
of course, are suitable for and applicable to all turpentine designed 
for the purposes for which it is usuaily employed, such as paint and 
varnish thinner, im polishes, pharmaceuticals, calico printing, etc., 
and are issued for the information of the turpentine producing and 
consuming indusiries. 
All recently made turpentine will comply with these specifications. 
Only that which has been stored im partially filled containers for a 
long time may not comply with those for specific gravity and distilla- 
tion, for the reason that on long storage in partly filled containers 
turpentine takes up oxygen, becomes thicker and heavier, and leaves 
a larger residue on drying or when distilled. Nevertheless, such 
partially oxidized turpentine may be and usually is suitable for 
thinning paints and varnishes which are to be used in hot weather or 
hot climates. or those which are used out of doors under favorable 
drying conditions or where slow drying is desired. 
Fresh turpentine will always meet these specifications. The pro- 
ducer who does not adulterate his turpentine and who keeps his 
storage tanks full or keeps turpentine moving through them need 
have no fear that it will fail to comply with these specifications. It is 
- suggested that the producer or dealer make a practice of always selling 
the stock which has been on hand longest, thus avoiding danger of 
excessive oxidation. 
The following specifications probably are the most complete 
that have ever been prepared for turpentine, and may appear, to 
dealers and producers especially, lengthy and likely to complicate 
materially transactions in turpentine. As previously stated, this 
need not be feared when the turpentine is pure and has been stored 
with proper care. The specifications proper, which are very simple, 
are covered in section 1, page 43; the rest cover the directions for 
taking samples (a highly important matter, since if the sample is 
not representative the results of examination will be misleading), 
