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us use every effoft to stimulate the use of whatever preservative is
used under its owa colors. It is a hopeful sign that the day is not
far distant when creosote distilling plants will sell their product sub-
ject to inspection as it comes from the stills. In the minds of many
consumers there has been too much connected with this industry which
has been mysterious. There is no reason for this, and there ought to
be none. We offer the specification for a coal tar creosote solution as
a step toward a better understanding of one phase of the industry.

During the reading of the paper Dr. von Schrenk interpolated the
following :

During the last year in co-operation with the Barrett Manufactur-
ing Company we made a number of different mixtures, using typical

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American Wood Preservers' Association 157

coal tar of known chemical composition and mixing these with a
standard creosote oil. In the tables we have presented in this paper
the results as determined by us are given. It will be easy to refer to
these tables and examine the results. The letters A, B and C refer to
the tars and figures following the letters in each series represent the
percentage of coal tar mixed with a certain percentage of creosote oil,
from which we get combinations 10, 20 and 30 and determine the dis-
tilling points, the viscosities and the usuat water percentages.

That specification is one which says practically very little more
than that the material is a coal-tar compound and we frankly recog-
nize the fact that it is a combination or a solution, because I don't like
the word mixture. It is really a chemical solution, a solution which
shall practically have a reduced amount of residue and which shall
have a specific viscosity, both of which points will more or less materi-
ally tend to hold down the percentage of the amount of coal tar which
it would be possible to put into the solution. You will note that the
important features of this specification are that there should be very
little distilled below 200° ; that a maximum of 26 per cent, is allowed
for the residue above 355**, and that the viscosity in no instance, when
using the standard -Engler apparatus, 280°, shall not at any time exceed
59 seconds.

THE PRESIDENT: We have one written discussion by Mr.
Hendricks, of the Frisco, on this paper which we will now have read.

Secretary Angier then read the written discussion as follows:



By V. K. Hendricks.

While I cannot offer any constructive discussion on this paper, at-
tention is called to the fact that the authors themselves do not con-
sider their suggested specification as being at all final; and in view of
our lack of information I should personally be inclined to have the cre-
osote and tar procured separately and mixed under the direct supervi-
sion of the user rather than to purchase a preservative under a specifi-
cation which might not prove to be* what is desired. There is, of course,
a chance of having a mixture furnished as creosote oil instead of having
straight creosote oil furnished, but I should personally prefer at this
time to accept that risk rather than the risk of an untried specification,
in case I were usmg a mixture of tar and creosote.

In their paper the authors make no mention of free carbon, except
that the specification provides that the oil shall consist only of coal-
tar distillates and oils obtained by the "filtration of coal-tar." So far
as I am aware, the tar which has been used in admixture heretofore has
not ordinarily, if in any case, been filtered, but it was obtained from

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158 Eleventh Annual Meeting

such sources that the amount of free carbon was comparatively slight.
In the paper by Mr. F. M. Bond on "Some Tests to Determine the
Effect Upon Absorption and Penetration of Mixing Tar with ' Creo-
sote/* published in our 1913 Proceedings, some of the conclusions given
on page 273 are as follows:

3. There was no apparent relation between the viscosities and spe-
cific gravities of mixtures of creosote with the three carbon-free tars and
the corresponding absorptions and penetrations into longleaf pine.

7. There was no apparent relation between the amounts of free
carbon in mixture of creosote with the three normal tars and the corre-
sponding absorptions and penetrations into longleaf pine.

8. There was no apparent relation between the vicosities and spe-
cific gravities of mixtures of creosote with the three normal tars and the
corresponding absorptions and penetrations into longleaf pine.

Judging from the results of Mr. Bond's experiments it would seem
that the -question of free-carbon content and the size of free-carbon
agglomeration should be given further investigation.

There are no doubt a number of other questions on which ad-
ditional information should be obtained before a thoroughly compre-
hensive specification for a mixture of tar and creosote can be drawn.

DR. H. VON SCHRENK : May I make a reply to one or two
criticisms ?


DR. H. VON SCHRENK: As I understood it was said that
there is no reference to the free-carbon question in this specification. I
would like to refer to the specification, which says in the second line:
''Matter insoluble on hot extraction with benzol shall not exceed 2 per

THE PRESIDENT : Mr. Hendricks, will that answer your criti-
cism on that point ?


MR. A. E.. LARKIN: We would like to present a discussion
somewhat along the same lines. When this paper was presented we
found that the question raised by Dr. von Schrenk was one that inter-
ested our company very much, and I asked Mr. Reilly to prepare a
paper to be presented at this time, for I wished to read it in connection
with Dr. von Schrenk's paper in order to give two sides of the matter
and to encourage further and freer discussion of the question.



By P. C. Rcflly.

Dr. von Schrenk undoubtedly submitted his paper for the pur-
pose of encouraging discussion on creosote oil and of its mixture with
coal-tar and probably, as well, with the view of having the American

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American Wood Preservers' Association 159

Wood Preservers* Association decide upon a proper classification of
the mixture of coal-tar and creosote oil. He submits the term "A
Coal-Tar Creosote Solution" for consideration as a proper designation
for the mixture of coal-tar and creosote oil.

There are, therefore, in his paper three points to consider:

1st. The mixture of coal-tar with creosote oil and the quality of
this mixture.

2d. What name should be given to the mixture oi coal-tar with
creosote oil.

3d. Creosote oil.

The term "Coal-Tar Creosote Oil Solution" cannot be adopted for
the mixture of tar with creosote oil because it is not descriptive of the
mixture. It is without specific meaning, because of its failure to desig-
nate the material to be dissolved in making the solution. If the term
"solution" is to be used to describe the addition of coal-tar to coal-tar
creosote oil it should be expressed in the following words: "Creosote
Oil Solution of Coal-Tar;" and if petroleum-tar is added to creosote
oil it should be described as "Creosote Oil Solution of Petroleum-Tar."
The tar is the article dissolved, and the "solution," therefore, is a tar
solution. For instance, when zinc is dissplved in water, the water
being solvent, we do not classify it as a water solution. Such a desig-
nation would be incomplete and, therefore, meaningless. The article
dissolved is zinc, and the resulting solution is a zinc solution, classified
as such. Water is the solvent for the zinc; creosote oil is the solvent
for the tar. For these reasons I believe the mixture should be charac-
terized as a "Creosote Oil Solution of Tar" — the kind of tar used,
whether coal-tar or petroleum-tar, to be designated specifically.

It is difficult to imagine any article of commerce being treated so
badly and unscientifically as creosote oil has been. The manufacturers
of it, until very recently, were careless in its production, and its quality
has been good and bad and consequently very uniform. We should not
further impose upon it by adulterating it with coal-tar and make its
name, as in the case of the suggested description, carry the burden ot
the adulteration without mentioning the adulterant. It will be ob-
served that although the purpose of the specification is to permit the
use of coal-tar, the word "coal-tar" as referring to the material itself,
is omitted from the suggested designation for the specification. Its use
as an adjective in qualifying the creosote oil is all right, but you will no-
tice it in no way refers to the adulterant used.

Another criticism can be made of the specification submitted by Dr.
von Schrenk, which will probably lead to the production of a clearer
and more easily understood specification than the one submitted by
him. His specification reads:

The oil shall be a pure coal-tar product, consisting only of coal-tar
distillates and oils obtained by thfl|^ltration of coal-tar.

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160 Eleventh Annual Meeting

Here again the word "coal-tar" is omitted and the word "oils" im-
properly substituted therefor. Coal-tar filtered is coal-tar. Filtration
simply removes the free carbon and other foreign substances. There
are no oils filtered out from coal-tar. This specification, therefore,
whenever used should be written as follows:

The oil shall be a pure coal-tar product, consisting only of coal-tar
distillates and filtered coal-tar.

Dr. von Schrenk further states:

The mixtures in the two series are with the same quantity, but the
mixtures are made in a slightly different way.

I wish he would explain how the mixtures were "made in a slightly
different way" yet when tested ^ave different results, as shown in
Tables II and III.

Those engaged in the wood-preserving industry should discounte-
nance the use of any adulterant and should instead exert their efforts
to improve the quality of their products by improving the quality of
the oil used. With the exception of the action of the American Rail-
way Engineering Association to establish a specification for tie treat-
ment of uniform quality, and the determination of some cities to estab-
lish a standard of quality for wood paving blocks, there has been no
general or consistent attempt made to improve the quality of this
important commodity. The improvement by the American Railway
Engineering Association consisted only in establishing a standard for
the oil being offered them; it made no attempt to improve the quality
of the commodity itself. This record is not a very enviable one for the
product itself or for its manufacturers.

Coal-tar distillers and wood-preserving people have invited criti-
cism, because of the indifference they have shown in the manufacture
and production of creosote oil. We are at present doing nothing more
than working with a grade of creosote oil prepared by Bethel nearly
100 years ago. This is not advancement. In Bethers time a mixture
of tar and creosote oil was tried, but discontinued, because it was
found that the tar was only an impediment to the injection of the
creosote oil. I do not know the carbon content of the coal-tar used
at that time, but it was probably somewhat higher than the present coke
oven tars. But even using filtered coal-tars the pitchy part of the
tar remains on the surface of the timber and acts as an impediment to

It is clear that it is a step backward to mix tar with creosote oil,
because anything that debases or affects adversely the quality of a
product is a backward step. The admitted inferiority of the adulterated
oil alone should bring its condemnation and prohibit its serious con-


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American Wood Preservers' Association 161

Is it not astonishing that with nearly a century's experience behind
us and with the present-day progress and advance in other branches
of industry that we have nothing better to suggest than the adul-
teration of an article upon which the very success of our industry is
based? If improvement were impossible, and if all efforts to make
creosote oil better and more efficient had proved failures, then there
might be reason for us to cling to Bethel's grade of pure creosote oil ;
but there can be no excuse for adulterating it. But improvement in the
quality of creosote oil is not impossible. The experience we have had
and the d^ta at hand conclusively show us that we can produce the
quality of creosote oil best suited to our purpose. It is easy to improve
upon the present qualities of creosote oils ; therefore, why should not
the attitude be to do so and move forward a step rather than back-
ward? If we are not willing to move forward we should at least
be willing to cling to that which has proved comparatively successful.

I am aware that the claim has been made, and, no doubt, will be
made again when this paper is concluded, that the reason for the
proposed adulteration of pure creosote oil with tar is a commercial
necessity; that there is not nearly enough oil produced in this country
to supply the demand. I also expect the falling off in importations in
19.14, on account of the war, will be advanced as a reason for a per-
missible adulteration now. In any discussion of the supply of oil, the
temporary war condition should not be advanced as a reason for the
adulteration, or for the need of it, because the adulteration of creosote
oil has been going on for years and years, and it was then, a3 well as
now, in no way related to the supply of material at home or to the
importation from abroad. An analysis of the percentages of coal-tar to
be mixed with creosote oil, as suggested by Dr. von Schrenk, will, I
think, dispel the supposed necessity for the adulteration, because of
the shortage of our creosote oil production. Roughly speaking, our
consumption of creosote oil is 100,000,000 gallons annually, of which 40
per cent., or 40,000,000 gallons, is produced in this country. If we add
10 per cent, of coal-tar to it, it means an added production of 4,000,000
gallons ; if we add 20 per cent., it means an added production of 8,000.-
000 gallons; if we add 30 per cent., it means an added production of
12,000,000 gallons. Assuming that it would be permitted to adulterate
all of the home production, we would still be short, respectively, 56,000,-
000, 51,000,000 and 48,000,000 gallons, which we would have to get from
abroad. This assumes also that all of this tar will prove to be a
preservative and penetrate the timber, which, of course, is not the
case. But these figures, even if taken in the exaggerated form as here
given, show that the adulteration will not bring any measurable relief,
that we would still have to depend upon Europe, and that to get this
alleged increase it would be necessary to convert a large volume of

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162 Eleventh Annual Meeting

first-class oil into a slightly increased volume of inferior oil. It seems
to me that the result of the theory repudiates the theory and shows
that it is a matter not warranting serious consideration. But it might
be asserted that the adulteration in the proportions mentioned could
be added to the total quantity of creosote oil, imported and domestic. I
think to assume that the buyers of substantially one-half of the oil con-
sumed might be willing to use a mixture with the mark of inferiority
stamped upon it is assuming that a very large — ^too large — 3. proportion
would accept the adulterant.

It is difficult to understand the persistent efforts in recent years to
promote the adulteration of creosote oil with coal-tar. It is acknowl-
edged that the adulterated mixture is inferior to the unadulterated
creosote oil. And the figures show that no real relief from the short-
age in production in this country is^ obtainable by the use of tar. The
questioii of the use of tar as an adulterant in the creosoting industry
must, therefore, be purely a commercial one with those having the tar to
market and with which treating engineers and those engaged in the
promotion of the wood-preserving industry have no connection, because
they do not understand, and should not be expected to understand,
the actual basic conditions with respect to the coal-tar industry. All
of us are inspired by the same high motive as Dr. von Schrenk, that, if
the material is not to be had first in this country, or second from
abroad, then seek something else in this country to supply the defi-
ciency. The field is here to obtain the suitable material if we seek it.
And if the coal-tar distillers properly co-operate with those engineers
in wood-preservation as well as with the consumers of creosote oil the
production of oil in this country could be considerably increased above
the largest quantity of tar which Dr. von Schrenk recommends as a
partial relief from the shortage existing. The delinquency in this
matter can be traceable to those engaged in the coal-tar industry.

Not long ago one of our engineering papers published the fact
that a large quantity of coal-tar had been destroyed and kept from
the market. Whether it was destroyed to keep it from the market or
not is not material. The fact that it was destroyed, while there
existed a shortage of creosote oil, is material; and this destruction has
prevailed in the coal-tar industry for years. There is an old proverb:
"Waste not, want not." It is also a truism that you cannot destroy
a thing and have it too. Suppose that instead of destroying this tar
for years and years, when the importations of creosote oil were in-
creasing to supply a large local demand, it had been refined, and 33
per cent, to 40 per cent, of it had been saved in the form of creosote oil,
and the refuse, if useless, thrown away, what would have been the
present condition? The supply of creosote oil produced would have
been so large that it would, I am sure, easily have satisfied any deficiency

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American Wood Preservers' Association 163

which occurred beyond the present supply. Would it not be better for
the American Wood Preservers' Association to- go on record as advo-
cating the conservation of coal-tar, the source of creosote oil, and
converting as much of it as possible into creosote oil, thus increasing the
quantity rather than favor the debasement of the product? Would
not such a course be more in keeping with the object of the Association
than to approve so uneconomical an expedient as is being advocated and
one that would cause us to regulate our business so as to conform to
such destructive policy ? I contend that there is no necessity for debas-
ing our material by adulterating it with coal-tar. Instead of making
coal-tar a debasing medium, the coal-tar interests should not only
improve the quality of their creosote oil, but should also increase their
production of it by not wasting the raw material, especially when the
waste creates an artificial shortage.

I have found that the degree of penetration of creosote oil is
reduced by the addition of coal-tar, and the larger the addition of
the tar to the creosote oil the greater the decrease of the penetration
of the "solution." This is a natural consequence, resulting from the
addition of a material (tar) haviijg a very high viscosity and low
co-efficient of penetration. In fact, the so-called "solution" (tar added
to creosote oil) is not altogether a solution, but in part a mixture, and
that part of the material which is not entirely dissolved is separated
from the solution by the straining nature of the wood fibre, which acts
as a filter cloth when wood is treated with the "solution," and there is
deposited on the surface of the wood a heavy viscous pitch. This
dense, pitchy coating is the element which hinders the free and even
penetration of the solution.

The mixture of the t|ar and creosote oil, in comparison with the
pure creosote oil, will illustrate very nicely that there is no relation
between viscosity and gravity, and also that there is no relation
between viscosity and penetration. The tar mixture in the viscosi-
meter tests acts as a mixture of oil and water, thoroughly mixed, will
act. The mixture would flow through the viscosimeter without separa-
tion and its viscosity would be recorded. But if this mixture of oil and
water is filtered, the water will filter out from the oil. So, with the tar
mixture, when it meets with resistance, as it does when it comes in con-
tact with the timber, the oil filters out from the pitchy tar.

I have made tests with the Tagliabue viscosimeter, using the per-
centages of tar in mixture with creosote oil mentioned in Dr. von
Schrenk's paper, and have compared each of the mixtures containing 10
per cent, 20 per cent, and 30 per cent, of tar with pure creosote oil itself
with the following results :

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164 EiyE^vE^NTH Annual Me^eting



70% Cre6. 30% Tar

Sp. Gr...,. 38»C

Distilling to 200" C

" 235»C

" . 315»C



Viscosities at







Creosote Oil, Sp. Gr

Coal-Tar " " "

38 »C





I have also taken a creosote oil heavier in gravity than the tat
mixtures advanced by Dr. von Schrenk, and I have observed that the
heavy creosote oil has a lower viscosity than the creosote oils adulter-
ated with tar. Dr. von Schrenk makes the statement that the viscosity
of the tar mixture increased in proportion to the increase of the
gravity, as the percentage of tar in the mixture increased, and he
states that this might have been expected. It is to be expected from a
mixture of tar, not because of the increase in the gravity of the material
but because of the pitchy non-penetrating substance in the tar — from
the very nature of the material itself and its lack of mobility. An
increased viscosity under such conditions as stated by Dr. von Schrenk
is due to the pitch in the tar, which substance it is known interferes
with the penetration of the mixture into the wood. Conversely, take
the viscosity of the tar itself. Dissolve the tar in creosote oil, and as
the percentage of the creosote oil is increased, the viscosity of the
material will be decreased. The viscosity of pure creosote oil, of the
same gravity as the tar mixture, is much less, showing there is abso-
lutely no relation between viscosity and gravity of these materials. This
increased viscosity of the tar mixture explains why any engineer or
person skilled in the treatment of timber cotisiders the pure creosote
oil as a better medium for treating wood than when it is adulterated
with tar or any other material which acts as a retardent to the penetra-
tion of the oil.

The oil used in our industry should have the greatest penettating
qualities, should be high in antiseptic properties and should not be
subject to great volatilization under natural weather conditions, quali-
ties of highest importance for treatment of railway ties and paving

I have, I hope, set forth three cardinal principles for your con-
sideration :

First. That the adulteration of creosote oil with tar is unwise,
and, from a commercial standpoint, both as to increasing the quantity
of the preservative by mixing creosote oil and tar and the use of this
mixture, unnecessary, and certainly inadvisable.

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American Wood Preservers' Association 165

Second. That as the mixture of tar with creosote oil detracts from
the quality of the wood-preserving prc^erties of the creosote oil, it
should not be used.

Third. That whenever either coal-tar or petroleum-tar is used for
wood-preservation, the name of the tar so used should be frankly set
forth, both in the caption of the specification and in the specification

MR. A. E. LARKIN: I wish to call your attention to a section
from the Constitution and By-laws which I shall read as 'follows :

"See. 2, Art. I. The objects and purposes of the Association shall be
to advance the wood-preserving industry m all its branches; to afford its
members opportunities for the interchange of ideas with respect to im-
provements m the wood-preserving industrv, and for the discussion of all
matters bearing upon the industry of wood-preserving; to maintain a high
business and professional standard in all respects, anof to standardize speci-

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