90 
Transactions Texas Academy of Science. 
while those prepared with the low boiling oils, which also contained car- 
bolic acid, were attacked by decay. It is to the high boiling tar oils, 
then, that particular attention should be paid. These tar oils have 
strong germicidal effect — even the solids, such as napthalene, inhibiting 
the growth of lower forms of life. 
3rd. — Tar Bases. In examining these high boiling oils, tar acids are 
found to be absent, but tar bases, notably acridine and cryptidene, are 
found present. These tar bases are very effective germicides. Acridine 
is very slightly soluble, or practically insoluble, in water, and acts as a 
powerful germicide. It has been used to protect the sides of sea-going 
vessels against the attacks of barnacles and teredos. Even after an 
exposure of nine (9) months at sea, acridine was still present in the 
paint with which it was mixed, and the hulls were free from attack. 
This substance was found to be present in most of the samples of creo- 
soted timbers mentioned above, and it is the opinion of the highest 
authorities that acridine is one of the most important constituents of 
coal tar distillates intended for wood preservers. 
M. H. H. Cousins, of the Southwestern Agricultural College at Wye, 
England, carried out experiments with a view to throw light on the rela- 
tive preservative powers of various constituents of ordinary creosote. 
The following tables are taken from his report in the “ Analyst” of June, 
3900: 
Table 1. 
Breaking strain of string after ten (10) months exposure (original 
breaking strain, 33 lbs.). 
Treatment. 
Condition. 
Breaking 
Strain. 
Untreated 
Rotten..... 
With tar acids 
Rotten 
With volatile distillates from creosote... 
Rotten 
With Phenol 
Rotten 
With C resol 
Rotten. 
With Naphthalene 
Partly rotten 
3 
With tar bases 
1 in 6 rotten 
16 
With Bone oil 
Sound 
18 
With non-volatile oils from creosote 
Sound 
16 
Table 2 . 
Breaking strain (transverse) of deal rods exposed ten (10) months 
(breaking strain 630 lbs.). 
Treatment. 
Condition. 
Breaking 
Strain. 
Untreated..... 
Mnn.h deoa.yed 
300 
Tar acids 
Little decayed... 
430 
Tar bases........ 
Surface good 
360 
Napthalene.... 
Surface decayed, sound within 
410 
Non-volatile residue ........ 
Sound 
570 
Animal oil.... 
Sri r fare fair 
440 
Creosote 
Sound 
470 
Oresol 
Mri eh der.ayed 
330 
