968 T H E J O U R N A L O F I N D U S T R I A L

California, Nevada, Oregon, Kansas, New Hampshire, Connecticut, and Rhode Island-had established commissions for the control of public utilities. Massa- chusetts divided many of the same powers among three commissions, and several states gave a part of the same powers t o other commissions, such as, for example in Oklahoma, t o the corporation com- missions.

Following considerable agitation, eight states- Indiana, Illinois, Colorado, Missouri, Montana, Idaho, Pennsylvania, and West Virginia-created public utilities commissions during the legislative sessions of 1913. Massachusetts conferred the duties of the highway commission relating to telegraphs and tele- phones and the duties of the railroad commission upon a new public service commission; Ohio redrafted the public utility commission law, giving additional powers especially relating to valuation and to stock and bond issues; and New Hampshire amended her law by giving the commission power over accounting, including depreciation. In each case the commission is made appointive by the governor.

These laws uniformly require tha t public utilities shall give just and reasonable service a t a just and reasonable rate, and in most states the commissions are given ample power for investigation and enforce- ment. The municipal utilities placed under control in the different states are mainly heat, light, water and power companies, street railways, and telephone and telegraph companies. In most of the states,

A N D E N G I N E E R I N G C H E M I S T R Y Vol. 5 , No. 12

railroads, other common carriers and similar services are also controlled.

Discrimination is prohibited in service and rates; free service to any but certain excepted classes is prohibited, and, in all but West Virginia, issues of stocks and bonds are placed under the regulation of the commission; uniform accounts are provided for, either in a mandatory or optional way, and valuation of the #property used and useful for the convenience of the public is authorized in nearly all of the states. In Indiana and Ohio such valuation is required. In alm'ost every state municipally owned utilities are subject to the same regulations as others. The laws make no exceptions for home rule. A strong effort was made in Illinois t o except Chicago from the law, but it failed. It may be said in general that the state commission is supreme in most matters over the municipalities, although much power is left t o the latter t o regulate and control. The cities grant franchises and regulate by contract or otherwise the service and condition of occupying of the streets. In Indiana the indeterminate permit is provided for after the manner of the Wisconsin law.

A consideration of the new public utilities acts shows tha t there.is a tendency to give real powers to the commissions. With the exception of the laws passed in Massachusetts and West Virginia, the acts of the year represent nearly all of the best which have been demonstrated to be empirically good in other states. W. A. HAYOR

I ORIGINAL PAPERS 1 THE PROTECTION OF IRON AND STEEL BY PAINT

FILMS B y NORMAN A. DUBOIS Received October 4, 1913

The theories of corrosion of iron and steel which have received consideration and which still seem to have their defenders and opposers are interesting to note. The carbonic acid theory in brief requires the presence of carbonic acid to start corrosion. The peroxide theory supposes tha t hydrogen peroxide is formed in the presence of moisture and oxygen, and tha t this hydrogen peroxide causes corrosion. The electrolytic theory assumes that iron passes into solu- tion in water in the form of a ferrous ion before it can oxidize. A more or less complete discussion of these theories may be found in the various journals and other publications. It is not the purpose of this paper to discuss them. . From the standpoint of the paint technologist

the problem is tha t of finding the paint film which will enable him to protect the exposed surface of iron and steel from the various rusting influences for the longest possible time. The theories of corrosion and numer- ous discussions of them have been of inestimable value, and the proper interpretation of them has enabled the paint technologist t o improve his paint film. Let us briefly consider these theories from the stand- point in question.

The carbonic acid theory requires the presence of carbonic acid tha t corrosion may proceed. In other words, considering a paint film properly applied over the surface of iron and steel i t requires tha t carbon dioxide shall pass through this film, and also tha t water, either as such or in the form of aqueous vapor, shall pass through the film, and there in conjunction with the carbon dioxide react as carbonic acid. The imperviousness of the paint film to carbon dioxide gas and to aqueous vapor, then, is the vital quality from the standpoint of this theory. The more im- pervious the paint film to the gases carbon dioxide and aqueous vapor, the longer it will protect the iron or steel from corrosion.

The peroxide theory requires the formation of hy- drogen peroxide on the surface of the iron or steel. Considering a paint film properly applied over t h e surface of iron or steel, therefore, this means tha t the less pervious the paint film is to the gases oxygen and aqueous vapor, the smaller will be the quantity of hydrogen peroxide formed on the surface of the iron or steel, and the longer it will protect the iron or steel from corrosion.

The electrolytic theory requires tha t iron first pass into solution in water as ferrous ion, and that it is then acted upon by oxygen dissolved in the water or by carbon dioxide and water t o form rust. Again considering a paint film properly applied over iron or'

969 Dee., 1913 T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERI lVG C H E M I S T R Y

steel this theory requires the presence of water in which the iron may dissolve to form ferrous ions, Obviously, the only way the water can get t o the iron or steel is t o pass through the paint film, as such, or in the form of aqueous vapor. If we suppose the ferrous ions have been formed, the action can go no further in the ab- sence of an oxidizing agent, presumably oxygen, which in turn must get through the paint film. The reasoning for the presence of other gases is similar. We find, therefore, t ha t for corrosion t o proceed ac- cording to the electrolytic theory ihe gases, aqueous vapor, oxygen, or others must pass through the paint film, and as in the other cases, the mare impervious the paint film t o gases and moisture, the longer i t will protect the surface of the iron or stecl from corrosion.

This is hut t o conclude tha t the paint film which will serve for the longest time as a protection to iron or steel against corrosion is the one which is the least pervious to aqueous vapor, the gases oxygen and carbon dioxide, or in fact any gas in the surrounding atmosphere which may in any way cause or accelerate corrosion.

If we assume the corrosion to be entirely due t.o the deterioration of the paint film rather than to its permeability to aqueous vapor and other gases, the same conclusion holds, as the rate of deterioration will be proportional t o the permeability of the film to the deteriorating elements.

The clectrolytic theory of corrosion has given rise to a division of pigments into three classes: corrosion accclerators, corrosion inhihitors, and inerts. While these pigments seem to give results as predicted by this theory in the presence of abundance of water or when tlie iron or steel is actually immersed in water, i t does not neccssarily follow that they will do so, t o a like extcnt a t least, when incorporated in a paint film where conditions are much different.

Assume, for instance, t ha t our paint film is some- what pervious to aqueous vapor and other gases. It follows that just as moisture may enter t o the iron or steel surface and perhaps give conditions under which the electrolytic theory may apply when outside conditions are damp, this moisture may also pass from the steel surface outward when outside conditions are dry, and thus leave the steel surface dry in a.hich case the electrolytic theory cannot possibly apply. As a matter of fact , the actual conditions existing on the surface beneath the paint film, in most instances, are very probably between the two extremes of some- what damp and nearly dry, and this is far from being covered with an abundance of water a t all times, the conditions under which the electrolytic theory seems to work out well. This reasoning is borne out by the fact that a picce of bright steel immersed in water containing a little zinc chromate in suspension will remain bright perhaps indefinitely, while the same pigment in a paint film under ordinary conditions will not protect the steel in a like manner.

Again, two paints composed of the same vehicle, but the first containing a so-called corrosion accelerator only, painted on a steel surface in a locality of ordi- nary dryness will outlast t o a great extent the second containing a rust inhibitive pigment painted on a

steel surface in a locality habitually very damp. This reasoning seems t o indicate and the evidence

seems to bear out the conclusion tha t the problem of iron and steel preservation is rather t o be solved by making our paint film as nearly impervious to gases as possible, than by trying to prevent corrosion by the addition of the so-called inhibitive pigments.

The problem is a physical one rather than a chemical one, and a comparison of paint films as t o their rela- tive obstruction to the diffusion of gascs will tell more regarding their value as protection against corrosion than a study of the inhibitive action of their pigments. This is not to say tha t the inhibitive property uf certain pigments is not worth consideration, but the imperviousness of the films is of f a r greater importance.

The work to be described here was carried out for the purpose of determining whether a special formula paint made according to the foregoing principles, embodying diffusion retarders, would not outlast in pro- tecting qualities those made according to thc formulas accepted as first quality paints for their respective purposes.

Our prime object is t o make the film as impervious t o gases as possible. This may be accomplished to a certain extent by special treatment of the vehicle and by incorporating special pigments and pi, <yment comb'nations. It is well known that a film from the oxidation of purc linseed oil, i. e . , a film ol linoxin, is more or less permeable to moisture and gases. It is marc or less porous. If other oils or gums, or similar materials, can be incorporated with the linseed oil t o form a homogcneous mass which as a whole acts as a perfect vehicle as regards compatibility of properties, it is readily understandable that such treatment may, t o an extent, fill the intermolecular spaces between the linseed oil mo!ecules, just as in other cases of solu- tion, alloy, or mixture; and this compound vehicle will he more dense, will leave a film which offers more resistance to the diffusion of gases, and wilt, there- fore, protect the iron and steel for a longer timc (as- suming other things equal) than a film which has not been treated in this way.

PLAIB I - S V ~ L PANBLS PAINIBD WITH PUNTS OP SAM% F o n ~ o ~ n ExcePr ONB CONSTIIVBNT OF ?BE V E X K L B

Plate I shows five steel panels which, after thorough cleaning with hot IO per cent solution of sulfuric acid for twenty minutes, washing by immersion in dilute caustic solution, thoroughly washing with water, and quickly drying, were painted as follows. All paints were of the same formula, with the exception of one constituent in the vehicle.

970 T H E J O U R N : i L O F I N D U S T R I A L

Panel A is a pure linseed oil vchicle. Pancl B contains j pcr cent of Kauri mixing varnish

Panel C contains I O per cent of Kauri mixing varnish

Pancl D contains 20 per cent of Kauri mixing varnish

Panel E contains 30 per cent of Kauri mixing varnish

These werc exposcd in a closcd box with a glass front, in order that the conditions cou'd be carefnlly watched. Oxygen and the corrosion accelcrating gases in thc atmospherc were passed into the box through wash bottles, t o insure a slow but steady cur- rent, and a small quantity of steam was admitted t o keep the atmosphcre within the box always very moist, hut not sufficient t o raise the temperature materially. The panels werc cxamined from day t o day, and removed when i t was judged tha t further exposure might obliterate the truths for which we wci-e seeking.

It. is very evident t ha t the pancls a t both ends have failcd before those betw-ecn. A relation may also be seen between the duration of protection and the quantity of Kauri mixing varnish in the vehicle. The protecting qualities increase with the per cent of Kauri mixing varnish to a certain point, and then fall off again as the pcrcentage of Kauri mixing varnish is increased beyond this point. This seems to indicate a definite point of maximum sealing effect for this particular material.

Another illustration of making a paint less pcrvious and thercfore a better protection against corrosion, is the proper choice of pigments. Ked lead and iinsecd oil have been long looked upon as the best primer for iron and steel. This may be truc, but is i t not possible to improve this red lead and linseed oil without seri- ously changing its nature and obtain a film which is less pcrvious to gascs and moisturc and thereby protect the iron and steel even more eflectivcly than

in the vehicle.

in thc vchiclc.

in the vchiclc.

in t hc vehicle.

PLAT6 SI-Paras UP SrenL PANBLS

A's primed with special red lead paint S3s primed with usual i rd lead paint All p ~ i n t e d wit11 same second coat paint.

will the red lead and linseed oil? If we shake o f f some of the traditional bonds and apply the teachings of more recent scientific investigation w e find i t possible by using the forcgoing principles and the proper chcice of particle sizes, making use of the law of mini-

A N D E N G I N E E R I N G C H E M I S T R Y Vol. j, No. 12

mum voids, t o produce a red l e id primer, which has all the advantages of the traditional red lead and lin- seed oil, and is a t the same time less pervious, and therefore a better protection against corrosion.

Plate I1 shows a sc.ries of pairs of steel panels, which have bccn cleancd in the usual manner with acid, ctc. Both A and B of each pair R C ~ C paintcd with thc same second coat paint, and each pair with a different second coat paint, while A of cach pair was primed Tyith n special red lead paint. formulated ac- cording to the principles just mentioned, :%nil B of each pair wiis primcd with red lead and linseed oil mixed according to a formula considered to givc thc bcst rcsrilts obtainablc after many years of practical painling under more or less adverse conditions of mois- ture and corrosion accelerating gases. All the panels werc painted in exactly the same manner on the same

PLATS 111-Pntns or Srmx PANSLS PAINTFD NLTH S O - U L L ~ RUST PnooF PAXNTS

Alr primed with special red lead paint B's primed with rust proof paint All second coat* of lust proof paint

day, allowed the same time t o dry between coats and also after the second coat, and exposed as previously described a t the same time and for the same length of time. Since the second coat on A and 13 is the same in each instance its effect has nothing whatever t o do with the comparison, this being dependent cntirely on the difference in the red lead priming paints on A and B. It can be seen a t a glance that the special red lead paint on A has given a much more efficient pro- tection than tha t mixed according to the prevailing custom on B. #ne hundred and twenty comparison pancls were exposed in this test and in every instance panel A showed a better film than did panel B.

Lastly, let us take up for a brief space the incom- ing of the throng of fantastically nem'ed "paints" which have been put on the market with claims equally as fantastic. Many of thcsc have been claimcd to protect the iron and steel as a primer and as a second coat better than anything on the market. It i s only ncccssary t o rcfer t o Plate 111, which is a photograph of some pairs of stecl pancis pre.pared as bcforc men- tioned and painted with a number of so-called rust inhibitive or rust proof paints. On panels marked B was painted two coats of a paint, and on pancls marked A one coat af the same paint over B priming coat of the special red lead paint formerly mentioned. As a diiierent paint is on each pair there are as

Dec., 1913 T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y 971

many different paints as there are pairs of panels. I t is readily seen tha t the two coats of any of these

paints, B, do not protect as well as where it is applied over the special red lead primer, A.

Blue lead seems to have certain properties very similar t o red lead when used in a paint for the priming of iron or steel, and in fact it is very possible tha t i t may be fully as good for this purpose as red lead, when properly used, if not better. Experiments are now being conducted by the writer to determine these relations.

Recently the idea has been set forth tha t certain pigments are rust inhibitive by virtue of their alkaline qualities. Further investigation seems necessary to determine whether i t is simply the alkaline properties of these pigments considered as a rust inhibitive only which endows the paint film with superior protecting qualities.

The suggestion may not be out of place tha t the basic properties of certain pigments enable them to attack the vehicle t o a sufficient extent t o form a small quantity of metallic soap which acts as a bind- ing material between the pigment particle' and the linoxin, thus offering a greater obstruction t o the passage of disintegrating elements between pig- ment particle and vehicle; or perhaps acting as a diffu- sion retarder in the linoxin.

It is not the intention of the writer t o point out the shortcomings of any particular brand of paint or theory, bu t simply t o give results of experiment and interpretation of the same with a view to bettering the paint conditions for all concerned.

I n conclusion then, i t would seem tha t whatever the correct theory of corrosion may be, it is of first importance to the paint technologist t o construct his film in such a manner as t o exclude gases and mois- ture to the greatest possible extent, as without these no corrosion can possibly take place.

BOSTON LABORATORIES OF THE GORDON-HITTL CO.

THE OLEORESINS OF JEFFREY AND SINGLELEAF PINES By A. W. SCHORCER

Received September 25, 1913

The Forest Service for a number of years has been investigating the possibilities of utilizing various species of conifers for the production of naval stores. The following work on Jeffrey and singleleaf pines is a continuation of t he examination of the oleoresins obtained during the tapping experiments. The methods of analysis employed and the results obtained in the examination of other species will be found in an- other publication.'

The oleoresins of the pinon pine' (Pinus edulis, Engelm) and singleleaf pine (Pinus monophylla, Torr, and Frem.) are similar in composition, appearance, and odor. Both oleoresins contain large resin acid crystals and have a pungent characteristic odor. The volatile oils of the two species consist mainly of a-pinene and the sesquiterpene cadinene is found in the higher boiling portions. I n addition, @-pinene

1 "An Examination of the Oleoresins of Somc Western Pines," by A. W. Schorger, Forest Service, Biill. 119.

and probably limonene' occur in the oil from Pinus edulis while limonene occursinthe oil of Pinus monophylla.

Attention has been previously2 called to the con- fusion caused by lack of an exact knowledge of the species yielding heptane. The source of this substance has been variously ascribed to one or more of the fol- lowing species: Western yellow pine (P. ponderosa, Laws); digger pine (P. sabiniana, Dougl.); and Jeffrey pine (P. jeffreyi). It has been previouslyZ shown tha t the oil from Pinus ponderosa does not contain heptane and tha t the oil of Pinus sabiniana consists of nearly pure heptane. It is now possible to con- firm the work of Blasdale3 and Wenzel14 since examina- tion of authentic samples of the oleoresin of Pinus jeffreyi has shown tha t the oil consists largely of normal heptane.

The lack of uniform data in the literature regarding the resin acids is much to be regretted. The melting point of abietic acid from colophony varies from 1 3 5 ' ~ t o 1 6 5 ' . ~ Tschirch' states t ha t American colophony contains a-, P-, and y-abietic acids melting a t I jj", I 58 ', and I j3-1 54', respectively, and then obtains abietic acid, melting point 166-167 ', from rosin oil.*

Leuchtenberger,g working under Tschirch, examined the colophony of Pinus jeffreyi. Extraction of an ether solution of the colophony with one per cent (NH4)2C03 gave four per cent of a-Jeffropinic acid,

.CI0Hl4O2, m. p. 160-161'; nine per cent P-Jeffropinic acid, C12H1802, m. p. 81-82'. Extraction with one per cent Na2C03 solution gave 3 j per cent a-jeffro- pinolic acid, C14H2002, or C14H2202, m. p. 117-118'; 38.2 per cent P-Jeffropinolic acid, C14H~002, or C14H2202, m. p. 77-78". The acid isolated by the author from the oleoresin of P. jeJreyi melted a t I ~ G - I ~ I ' . The silver salt contained 26.16 per cent of Ag, agreeing with the formula C20Hj002. The acid from the colo- phony melted a t 13 7-8 ' crystallized from acetone and 14 j-6' crystallized from acetone and hydrochloric acid. a-Jeffropinic acid requires 39.51 per cent Ag and a-Jeffropinolic acid, C14H2002, requires 32.98 per cent Ag. To obtain acids of this formula i t would be necessary for the resin crystals existing in the oleo- resin to undergo profound alteration in heating t o 145" C. which is not borne out by experience. The action of acids and alkalies has a material effect on the melting point of the resin acid. Valentelo ob- tained an acid from French colophony melting in the crude state a t about 160'. When purified by solution in dilute sodium carbonate and precipitation with dilute sulfuric acid, the resin acid melted a t only 1 4 6 - 1 4 8 ~ .

EXPERIMENTAL Oleoresin of Pinus monophylla

Oleoresin.-Analysis of the crude oleoresin gave 1 LOC. cil., 29. 2 "An Examination of the Oleoresins of Some Western Pines," by

8 Blasdale, J . Am. Chem. Soc., 23, 162-4 (1901). 4 Wenzell, Pharm. Rev., 22, 408-14 (1904). * Fliickiper, J. grakl. Chem., 101, 235 (1867). 4 Maly, Sitzungsber. d . k . Akad . d . Wis. zu Wien, 44, 121 (1861).

8 Arch. Pharm., 245, 1 (1907).

A. W. Schorger. Forest Service, Bull. 119.

' I Die Harze und die Harzebehalter," 2nd ed., 1906, p. 660.

Ibid. , 245, 701-7 (1907). Atl i della R . Accad. dei Lincei, 1, [4 ] 13 (1884).