2 BULLETIN 989, U. S. DEPARTMENT OF AGRICULTURE. 
Pine-oil products of the composition recommended by the Hygienic 
Laboratory and of similar composition have been put on the market 
by a number of manufacturers. Many of the commercial so-called 
pine-oil disinfectants are adulterated with kerosene and other mineral 
oils, and their phenol coefficients fall far below that found by Steven- 
son (18) for the Hygienic Laboratory pine-oil disinfectant. 
The work reported in this bulletin was undertaken for the purpose 
of determining the physical, chemical, and disinfectant properties of 
pine-oil and other pine-distillation products in order to secure data 
to assist in the detection of the adulteration of commercial products, 
as well as to check up the statements concerning the deterioration of 
pine-oil disinfectant and its peculiar behavior against certain patho- 
genic organisms. 
PRODUCTION OF PINE OIL. 
Pine oil is obtained by the distillation of pine wood in closed re- 
torts. It is an essential oil the odor of which varies from a pleasant 
pine to a disagreeable empyreumatic, depending on the method of its 
manufacture and the refining processes used. There are two general 
processes for making it—destructive distillation and the so-called 
steam or steam-and-solvent method. The wood used is the same in 
either case. 
In the early days what was considered to be a vast, inexhaustible 
pine forest, beginning in North Carolina, extended down the coast 
through Florida and the Gulf States to eastern Texas. Soon the 
turpentine and lumber industries took most of the standing timber, 
and they have moved steadily south and westward from North 
Carolina, where they started, until they have almost reached the end 
of the forest in Louisiana and Texas. These industries left in their 
wake a large amount of waste in the form of stumps and dead and 
down timber. In the course of time, the outer layer rots away from 
this timber, and the resinous heart material remains, forming 
what is termed throughout the South “lightwood,” so called be- 
cause it is used to make fires and for lights, not on account of its 
density. As a matter of fact, it is heavy, some samples having a 
density as high as 1.075 (30). This is the wood ‘which is used for 
distillation. Most of it comes from the longleaf southern pine (Pinus 
palustris), although commercially any wood that is “ fat” enough, 
or contains enough resinous material, is used. This includes small 
amounts of slash pine (Pinus heterophylla) and shortleaf pine 
(Pinus echinata) (8) (19). Much of the wood is obtained in the 
course of clearing land for agricultural purposes. ~ 
DESTRUCTIVE DISTILLATION. 
The crude beginnings of destructive distillation are to be found in 
charcoal burning (27), which was carried out in open trenches, the 
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