Hop-poles, Wood Fences, Sfc, against Decay. 505 
specting the quality of creosote with which my correspondents 
were being supplied. The creosoting liquid, it was alleged, 
when applied exactly in the same manner as in former years, 
entirely failed to protect hop-poles against decay ; and Mr. F. 
de Laune, to whom the merit is due of having used crude 
commercial creosote for preserving timber more than a dozen 
years ago with great success, and of having introduced this 
protecting liquid to the notice of farmers in his article in the 
Journal of this Society, vol. xviii., Part I., p. 259, goes so far 
as to say that, according to his recent experience, wood impreg 
nated with creosote supplied to him a year or two ago became 
rotten more rapidly than he believes it would have been had 
it not been subjected to the creosoting process. 
Mr. de Laune's experience in past years, of having creosoted 
wood with entire success, compared with his recent failures, 
presents strong presumptive evidence of the quality of com- 
mercial creosote having become deteriorated of late years in 
some cases to an extent such as to make it unsuitable for the 
preservation of hop-poles, wooden railings, &c. 
Unfortunately we possess no analytical data upon which a 
reliable oj)inion can be based respecting the quality of the 
creosoting liquid which ten or twelve years ago, and even earlier, 
had been used most satisfactorily. It is therefore impossible to 
make a comparison of the chemical composition of the creosote 
used in former years with great success with that supplied in 
recent years, and alleged to be altogether inefficacious as a 
means of protecting timber against decay. 
The liquid used for creosoting timber, known commercially 
as creosote, is a fluid possessing a highly complex and variable 
composition. 
It is obtained from coal-tar, which, according to the kind of 
coal from which it is produced, yields the following products on 
distillation at a temperature rising to about 760° F. 
1. Pitch, remaining behind in the retort on distillation, and 
constituting the largest proportion of the products of 
distillation. 
2. Naphtha, or benzol, the most volatile of the coal-tar 
constituents. 
3. Ammoniacal liquor, which always mechanically adheres 
to or is mixed with the more specific tar-products of 
commercial coal-tar. 
4. Light and heavy oils of tar. 
The latter amount to from 20 to 30 per cent, of the coal-tar, 
and constitute the creosoting liquor which is used for pre- 
serving timber. 
Commercial creosote, in other words, is the portion of coal- 
2 L 2 
