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T H E J O C R N A L O F I X D I j S T R I A L A ATD E,VGI A\T E E RI S G C H E M I S T R Y
strength. It has been found t h a t , i n general, I O per cent oxalic acid best serves t h e purpose. I n about 30 minutes i t removes t h e iron stains satisfactorily. Tests upon various soil minerals showed t h a t , with t h e exception of apatite, i t did not affect t h e m appreciably; a n d in t h e case of apatite, although there is undoubtedly some effect, i t leaves t h a t mineral in a
I
determinable state. Of course, in any case calcite would be removed-a fact which renders very difficult the determination of small quantities of this mineral in discolored soils. BUREAUOF SOILS
u. s. DEPARTMENT OF AGRICULTURE WASHINGTON
LABORATORY AND PLANT REPORT OF THE SELBY SMELTER COMMISSION Received December 8, 1914
T h e filing of t h e report, findings a n d recommendations of t h e Selby Smelter Commission with t h e Superior Court of Solano County settles finally a n d conclusively t h e long continued controversy between t h e residents of Benicia a n d t h e adjacent agricultural country a n d t h e Selby Smelting and Lead Company concerning t h e alleged disagreeable a n d injurious effects produced b y t h e smoke from t h e Selby Smelter. T h e smelter operated b y t h e Selby Smelting a n d Lead Company is situated near Vallejo Junction in Contra Costa County, California, a t t h e western end of t h e Carquinez Straits. The City of Benicia is situated in Solano County at t h e eastern end of t h e Straits, about five miles from t h e smelter. During nine months of t h e year t h e prevalent trade winds blow t h e smoke from t h e Selby Smelter over a n d into t h e City of Benicia a n d t h e agricultural area lying between Benicia a n d Vallejo. On March 14, 1905, action was brought by t h e District Attorney of Solano County, California, in t h e Superior Court of Solano County, praying for a n injunction which would restrain a n d enjoin t h e i s e l b y Smelting a n d Lead Company from permitting injurious smoke a n d gas from t h e Selby Smelter t o blow over a n d upon t h e City of Benicia a n d t h e tributary country. T h e case was brought t o trial on August 7 , 1906, a n d judgment of t h e Court in favor of t h e Plaintiff was rendered on July 16, 1908. T h e decree of t h e Court was t o t h e effect t h a t during eight months of each year between t h e 15th of March a n d t h e 15th of November, t h e Selby Company was enjoined from discharging noxious gases a n d fumes into t h e open air in such a manner t h a t t h e same would be carried into a n d upon t h e City of Benicia a n d t h e tributary country in Solano County i n such quantities as t o be offensive t o t h e senses a n d t o interfere with t h e comfortable enjoyment of life a n d property. After motion for a new trial was made b y t h e Defendant a n d denied b y t h e Court, a n appeal was thereupon taken t o t h e Supreme Court of t h e State. On June 12, 1912, t h e judgment of t h e trial court mas affirmed b y t h e Supreme Court. During t h e period covered b y this litigation t h e Selby Company h a d been making efforts toward t h e elimination of some of t h e objectionable constituents of t h e smoke, these efforts having resulted in t h e removal of t h e major portion of lead, arsenic a n d sulfur trioxide from t h e smelter smoke,
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I
I n t h e spring of 1913, although t h e Selby Company maintained t h a t they had abated t h e nuisance, complaints mere made by t h e residents of t h e area t h a t a nuisance still existed, a n d t h a t t h e decree of t h e Court was, therefore, being violated b y t h e Smelting Company. Various considerations, among them the prospective heavy expense which would accrue t o both parties t o the litigation as a result of a trial of the Smelter Company for contempt of Court, led t o conferences of t h e attorneys representing both sides, which resulted in a n agreement t o submit t h e question of fact a s t o t h e violation of t h e decree of injunction t o a board of technically trained men, deemed b y both sides t o be qualified t o act in such a capacity, and equal financial responsibility of t h e parties in t h e expense of t h e Commission’s activities. T h e result of t h e agreement was t h e filing of a stipulation in t h e record of t h e cause providing for such a board. 0 R GA N I Z AT1 0 N 0 F C 0 M 31 IS S I 0 N
On M a y 2 2 , 1913, this board was organized as t h e Selby Smelter Commission, with the . following personnel : J. A . HOLMES, Director U. S. Bureau of Mines. (at the time of appointment Chief of the E. C. FRANKLIN Chemical Division of the Hygienic Laboratory of the L.S. Public Health Service), Professor of Organic Chemistry, Leland Stanford, Jr., University. RALPHA . GOULD,Chemical Engineer, San Francisco, Secretary of the Commission. The function of t h e Selby Smelter Commission was t o determine t h e facts a n d report its findings on t h e following: 1-1s the Selby Smelter operating in such a manner as to violate the decree of the Court dated July 16, 1908? 2-If the Defendant Company is violating the decree, what is the extent of the violation? 3-If the Defendant Company is violating the decree, what steps must be taken by the Defendant to avoid a violation of the decree? For the determination of facts, the Commission a n d i t s staff have carried on very careful and complete investigations of all matters which in t h e opinion of t h e Commission could have a n y bearing on t h e questions at issue a n d t o be answered. These investigations were made b y the following staff of trained scientific a n d technical men, no one of whom, otherwise t h a n in arriving a t t h e t r u t h , was directly or indirectly interested in t h e findings of t h e Commission: A E. WELLS,Metallurgist and Chief Chemist, in charge of Smelter Investigations and Field Work. C. B. DUTTON,Special Legal Agent, U. S. Bureau of Mines.
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T H E J O U R N A L O F I N D C S T R I A L A N D E‘VGINEERING C H E M I S T R Y
CHARLES F. SHAW,Professor of Agronomy, College of Agriculture, University of California. E. E. FREE,Soil Expert and Agronomist. J. W.BLANKINSHIP, Ph.D., Plant Pathologist. WYATT W. JONES,Plant Pathologist. Professor of Entomology, Leland Stanford, Jr., R. W. DOANE, University. D.V.M., Professor Veterinary Science, College C. M. HARING, of Agriculture, University of California. K. F. MEYER, D.V.M., Professor Bacteriology and Protozoology, University of California. Through t h e courtesy of Dean T h o m a s F o r s y t h H u n t , of t h e College of Agriculture, a n d Professor F. T. G a y , of t h e D e p a r t m e n t of Pathology, t h e Commission h a d t h e valued cogperation of several of t h e staff of t h e University of California. T h e facilities of t h e U. S. Bureau of Mines also were placed a t t h e disposal of t h e Commission a n d much assistance was rendered b y its staff of experts, especially b y Dr. F. C. Cottrell a n d D r . L. H. Duschak. T h e results of t h e investigations of t h e several experts were presented t o t h e Commission i n t h e form of reports, as given below: I--4 Detailed Study of Statements of Residents of the Selby “Smoke Zone” as regards the Presence of a Nuisance in the Area, by C. B. Dutton. a-Conditions in and around the Selby Smelter and the Selby “Smoke Zone,” by A. E. Wells. 3-Investigations to Determine the Extent of the Contamination of the Atmosphere in the Selby “Smoke Zone” by the Smelter Emanations, by A. E. Wells. 4-Investigations to Determine the Sulfur Dioxide Present in the Atmosphere in Places Outside the Selby “Smoke Zone,” by A. E. Wells. 5-Conditions of Plant Life in the Selby “Smoke Zone,’’ b y J. W. Blankinship. 6-The Occurrence of Sulfur Dioxide Injury to Plants in the Selby “Smoke Zone,” by Wyatt W.Jones. 7-Insect Pests in t h e Selby “Smoke Zone,’’by R. W. Doane. 8-Agronomic and Soil Conditions in the Selby “Smoke Zone,” by Charles F. Shaw. 9-Investigations of Live Stock Conditions and Losses in the Selby “Smoke Zone,” by C. M. Haring and K. F. Meyer. Io-Fumigation Experiments to Determine the Effect of Highly Diluted Sulfur Dioxide upon a Growing Grain Crop, by A. E. Wells. I 1-Investigations to Determine the Effects of Sulfur Dioxide on Man, by A. E. Wells. I 2-The Possibility of Reducing the Sulfur Dioxide Output from the Selhy Smelter, by -4. E. Wells. (a)-Investigations on the Gases from the Dwight and Lloyd Sintering Machines of the Selby Smelter. (b)-Studies in the Commercial Utilization of the Sulfur Dioxide Produced by the Selby Smelter. 13-Bibliography: The Effect of Sulfur Dioxide on T’egetation and Animal Life, The Chemists’ ‘Club Library, New York. T h e field investigations u p o n which these reports are based were conducted between June, 1913, a n d September, 1914. In collecting t h e d a t a for his report, hlr. D u t t o n interviewed t h e residents of t h e “ S m o k e Z o n e ” in a s thorough a n d as representative a manner as possible, a n d sought t o obtain directly their ideas concerning t h e e‘xistence of a nuisance. T h e opinion expressed as t o t h e existence of t h e nuisance a n d injury from t h e
Vol. 7, KO.
I
smelter smoke varied from t h e extreme of unreasoning radicalism t o entire indifference. A s t u d y of Mr. D u t t o n ’ s report reveals t h e fact t h a t t w o classes of odors h a v e been described b y t h e residents of t h e “ S m o k e Zone” as “smelter smoke;” one is undoubtedly t h a t d u e t o sulfur dioxide, a n d t h e other is t h a t of certain products from t h e refining of petroleum, t h e so-called “oil smell.” Judging from t h e statements of these residents, there can be no d o u b t t h a t in t h e past, u p until 1910 or 1911, there were prese n t a t times in t h e “ S m o k e Zone’’ fumes a n d gases possessing very disagreeable odors, t h e ‘ I oil smell,’’ which could not possibly h a v e been due t o smelter emanations. Subsequent t o 1911, ‘ioil f u m e s ” h a v e not been so prevalent, b u t occasionally t h e odor of sulfur dioxide has been detected. T h e conclusions derived f r o m Mr. Dutton’s report are t h a t among t h e greater proportion of t h e residents there is a t t h e present t i m e only slight, if any, legitimate objection t o t h e presence of “smelter s m o k e ” in t h e atmosphere of t h e “ Smoke Zone.” Under extremely unfavorable conditions a n d t o supersensitive persons, “smelter s m o k e ” m a y occasionally be smelled i n t h e area, b u t t o t h e fair-minded person such occurrences do not prevent t h e enjoyment of life nor are t h e y detrimental t o t h e health of t h e community. T h e Commission considers t h a t one of t h e most important phases of its investigations has been t h e direct determination b y chemical analyses of t h e sulfur dioxide contained i n t h e atmosphere of t h e “ S m o k e Zone.” This work was conducted under t h e superintendence of hlr. A. E . Wells, t h e Metallurgist a n d Chief Chemist of t h e Commission, with t h e assistance of eight trained chemists a n d six helpers, a n d is believed b y t h e Commission t o be t h e most extensive a n d exhaustive of its kind heretofore. S U L F U R D I 0 X I D E D E T E R MI N AT1 0 K S
F o r t h e determination of sulfur dioxide, a method has been developed which is believed t o be b y far t h e best yet used in work of this character, in t h a t i t combines in a most satisfactory manner those characteristics which p e r m i t “ instantaneous sampling,” rapidity of execution, easy field manipulation, a n d a high degree of accuracy. Concentrations of sulfur dioxide as low as 0 . 2 p a r t per million of air are rapidly a n d easily determined b y t h e method as developed a n d finally adopted b y t h e Commission. For t h e essential features of t h e method, t h e Commission is indebted t o LIr. J . R. Marsden, Chief Chemist of t h e Selby Smelter. For making observations in t h e field, t w o permanent laboratories were established, where sulfur dioxide determinations were made a t brief intervals daily, a n d a n automobile was equipped as a portable laboratory. by means of which determinations were made i n all p a r t s of t h e Selby “ S m o k e Zone,” as well as in m a n y places outside t h e Selby ‘ I Smoke Zone.” T h e field investigations t o determine t h e sulfur dioxide content of t h e atmosphere i n t h e Selby “ S m o k e Zone” extended from September 17 t o December
Jan., 1915
T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y
15, 1913,a n d from March I t o April 15, 1914,during which time 4862 determinations were made. During the same period about 7 0 0 determinations were made in places outside t h e Selby “Smoke Zone.” During t h e entire course of the investigations, special attention was given t o t h e metallurgical processes going on a t the smelter a n d t h e amount of sulfur dioxide eliminated from t h e smelter during t h e tests in the “Smoke Zone” has been checked by the staff of the Commission. Determinations were made when the wind conditions were t h e worst possible for t h e area, a n d when, a t t h e request of t h e Commission a n d under its supervision, t h e output of sulfur dioxide from the smelter was t h e highest possible. Other tests have been made with the smelter entirely closed down a n d with t h e wind conditions favorable a n d unfavorable t o t h e “Smoke Zone.” Every a t t e m p t has been made t o obtain these d a t a under all possible conditions, in order t h a t maximum, average a n d minimum figure might be obtained as t o t h e sulfur dioxide content of t h e atmosphere of the “Smoke Zone.” Of t h e total number of “instantaneous” samples (4862) t a k e n in t h e Selby “Smoke Zone” during t h e period of field work, 7 5 per cent contained less t h a n 0.2 paft SOz per million of air; 86 per cent contained less t h a n 0.4 part SO2 per million; a n d over 97 per cent contained less t h a n 1.0part SO2 per million ,parts of air. Only 2 1 samples, or 0.43 per cent of t h e total, contained more t h a n 2 . 0 parts SO2, a n d no sample analyzed more t h a n 7.1 parts SO2 per million. T h e higher concentrations were found only when puffs of the smoke from t h e Selby Smelter were drifted b y a gentle breeze over t h e most exposed portions of t h e “Smoke Zone,” a n d a t no time did a concentration greater t h a n 2.0 parts SO2 per million persist for a continuous period of more t h a n thirty minutes. T h e total time during the whole period of t h e Commission’s investigation t h a t the concentration of sulfur dioxide was more t h a n 2 . 0 parts per million a t a n y part of the “Smoke Zone” was 2 2 0 minutes, or 3 hours a n d 40 minutes. Only on six occasions was t h e concentration above 3.0 parts S O n per million, a n d t h e total time t h a t t h e concentration was above t h a t amount was 6; minutes. Within t h e city limits of Benicia itself, the maximum concentration of sulfur dioxide found was 2.4 parts per million, a n d only 2 1 out of the 2840 samples t a k e n in this portion of t h e “Smoke Zone” contained more t h a n 1.0part SO2 per million. I n t h e business section of San Francisco during calm mornings, t h e concentration of sulfur dioxide was found t o be as high as 1.8 parts SO2 per million. Under brisk wind conditions such as are prevalent during t h e late morning a n d early afternoon during the period of trade winds, t h e sulfur dioxide content was seldom over 0.2 part SO2 per million. On the Ocean Beach no determinable quantity of sulfur dioxide was found. I n Oakland a n d Berkeley, of t h e 148 determinations made, none showed a concentration of sulfur dioxide higher t h a n 1.0 part per million. One hundred a n d three determinations were also made in t h e vicinity of Richmond, which showed an average value of 1.1
43
parts SO2 per million, and a maximum content of 4.5 parts SO2 per million. I n Martinez and vicinity, 168 determinations we’re made. T h e average of these determinations was 0.23 part SO:!per million, a n d t h e maximum 1.7 parts SO2 per million. T h e results of these investigations show t h a t , on t h e one hand, although t h e atmosphere of other areas investigated show a higher constant concentration of sulfur dioxide t h a n t h e Selby “Smoke Zone,” the maxim u m concentrations in the Selby “Smoke Zone,” on t h e other hand, are higher t h a n those of a n y of the other areas investigated. These higher concentrations, however, never persist for more t h a n a few minutes. SENSITIVENESS O F HUMAN B E I N G S T O S U L F U R DIOXIDE
I n order t o determine whether the concentration of sulfur dioxide found in t h e “Smoke Zone” could be considered sufficient cause for a nuisance complaint, or could be injurious t o the health of people residing in t h e Zone, i t became necessary t o study the effects of high dilutions of sulfur dioxide upon man a n d t o determine t h e sensitiveness of various persons t o the gas. T h e following is a brief summary of the results of these investigations: Of the 60 subjects experimented upon, 3 2 of whom were previously acquainted with t h e gas, no one was able t o detect t h e presence of 1.0part SO2 per million of air. With concentrations of 2.0 parts SO2 per million several of the subjects detected the presence of something foreign in t h e air, but could not identify it, and 2 identified t h e gas b y taste. With concentrations of 3.0 parts SO2 per million, the greater proportion of t h e subjects acquainted with t h e gas were able t o identify i t , a n d a t 4.0 parts practically all were able t o do so. T h e greater proportion of t h e subjects not previously acquainted with sulfur dioxide did not identify the gas until t h e concentration was greater t h a n 4.0 parts per million. I n t h e investigations t o determine what concentration of sulfur dioxide would be considered a nuisance t o all persons, very little agreement was found between the ideas expressed as t o what was a nuisance. As a general statement, i t may be said t h a t concentrations of 3.0, 4.0 a n d even 5.0 parts SO2 per million were not considered to be a nuisaoce even if continfied for considerable periods of time; concentrations of from j . 0 t o 10.0 parts SO? per million if continued for I O t o 1 5 minutes would be considered a nuisance; concentrations above 10.0parts SO2 per million if existing for only a few minutes would certainly be called a nuisance. It was definitely determined t h a t concentrations below t h a t a t which the sulfur dioxide can be smelled, t h a t is, below about 3.0 parts SO?per million, cannot possibly be considered a nuisance or cause for discomfort. It will be recalled t h a t in the atmosphere of the city of Benicia the sulfur dioxide concentration never reached 2 . 5 parts per million during the whole period of the Commission’s investigations, a n d t h a t a t one of the most exposed spots in the “Smoke Zone’’ there were b u t six short periods when it was above 3 parts, reaching a maximum of 7 parts on one occasion only. I n view of the established facts therefore, i t is quite
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T H E JOURNAL OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
impossible t o maintain t h a t during t h e period of investigations b y t h e Commission t h e residents of t h e C i t y of Benicia or of a n y other p a r t of t h e “ S m o k e Zone” h a v e been subjected t o a nuisance a s t h e result of discharge of sulfur dioxide from t h e Selby Smelter. EFFECT OF SULFUR DIOXIDE
ON VEGETATION
E x t e n d e d experiments were conducted t o determine whether such concentrations of sulfur dioxide as are found in t h e Selby “ S m o k e Zone” are capable of doing a n y injury t o crops or other vegetation growing in t h e Zone. T h e plan of these experiments was t o allow barley plants t o grow normally in a n open field, a n d occasionally a n d for definite periods of t i m e t o subject t h e plants t o definite concentrations of sulfur dioxide. These experiments were carried o u t with t h e following object in m i n d : I-To determine the visible injury produced by definite concentrations of sulfur dioxide applied for definite periods of time. 2-TO determine the economic injury or decrease in yield resulting from the visible injury produced. 3-To determine the possibility of “iqvisible injury” to a growing grain crop and the extent to which this may take place. I n a field of growing barley, experimental plots four feet b y t w e n t y feet in area were laid out, a n d covered during periods of fumigation with a cabinet designed so as t o interfere as little as possible with t h e illumination of t h e plot. T h e sulfur-dioxide-air-mixt u r e was blown in a t one e n d a n d allowed t o escape at t h e other, i n such a w a y as t o maintain a steady s t r e a m of air containing sulfur dioxide t h r o u g h t h e cabinet during t h e fumigation periods. T h e length of t i m e of each fumigation varied between t w o minutes a n d one hour. Experiments were carried o n simultaneously on a f a r m near Vallejo a n d a t t h e University f a r m a t Davis. A t Vallejo, 106 plots, a n d a t Davis 3j plots were experimented upon, with results which were concordant in every respect. A concentration of 5.0 p a r t s sulfur dioxide applied for a n hour under ordinary humidity conditions produced considerable visible injury. Visible injury is produced o n growing barley b y concentrations of 1.0 p a r t SO2 per million of air if t h e length of t i m e of application is sufficiently great. T h u s , 3 fumigations of 7 hrs. each produced slight visible injury a n d n o reduction in yield, with air containing 1.0 p a r t sulfur dioxide per million. Sixty-two fumigations of one h o u r each, with 0.5 p a r t SO1 per million, irregularly continued through t h e growing period, produced very slight visible injury a n d n o reduction in yield. F r o m a s t u d y of t h e results of these experiments in connection with t h e information gained from t h e investigations u p o n t h e sulfur dioxide content of t h e atmosphere of t h e “ S m o k e Zone,” t h e Commission has f o u n d t h a t from t i m e t o t i m e conditions m a y arise u n d e r which slight visible injury will be visited upon susceptible plants growing o n t h e more exposed portions of t h e “ Smoke Zone.” Since, however, plants will e n d u r e a considerable a m o u n t of visible injury without a n y diminution of crop yield, t h e Commission
Vol. 7 , N o .
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concludes t h a t within t h e “ S m o k e Zone” no economic d a m a g e results from t h e smoke of t h e Selby Smelter. This conclusion receives convincing confirmation from t h e observations of t h e Commission’s plant pathologists, who h a v e found n o indications whatever of economic sulfur dioxide damage within t h e area of t h e “ S m o k e Zone.” It was found t h a t when t h e plants were a t one t i m e badly bleached this fact did not necessarily mean a decrease in t h e yield. A n u m b e r of plots badly bleached in t h e early stages of growth were observed t o recover rapidly, a n d i t was f o u n d t h a t their yield a t m a t u r i t y averaged within three per cent of t h e yield f r o m t h e check plots. Short t i m e fumigations repeated a great m a n y times, a n d of sufficient intensity t o keep t h e foliage bleached t h r o u g h o u t t h e season, were much more effective in reducing t h e yield t h a n were one or t w o v e r y strong fumigations. No economic d a m a g e or loss as expressed i n decreased yield of crops or decrease i n t h e fertility of t h e seed resulted from t h e t r e a t m e n t of barley plants with quantities of sulfur dioxide insufficient t o produce m a r k e d visible injury. T h u s there was n o indication of a n economic “invisible injury.” AGRICULTURAL
CONDITIOPU’S IN ‘(SXOKE Z O N E ”
For t h e determination of t h e condition existing in t h e “ S m o k e Zone” as regards t h e crops of various kinds a a d t h e m a n y kinds of plant life found therein t h e Commission engaged t w o plant pathologists of a high degree of training a n d of extensive experience i n t h e s t u d y of plants i n relation t o smelter smoke injury. E a c h was commissioned t o m a k e a complete plant pathological survey of t h e area, reporting all a b n o r m a l conditions which exist a n d t o trace, wherever possible, t h e actual cause of such conditions. T h e only conclusions which c a n be d r a w n from t h e work done i n t h e plant pathological survey are t h a t such poor conditions of plant growth as exist in t h e “ S m o k e Zone” are directly traceable t o one or more of t h e following causes : plant diseases, predacious insects, poor soil, poor cultivation, lack of water a n d indifference t o all of those conditions b y t h e farmers of t h e area. None of t h e conditions existing so far a s vegetation is concerned c a n be a t t r i b u t e d t o t h e effects of t h e smoke from t h e Selby Smelter. F r o m a consideration of t h e d a t a collected during t h e entomological survey,the general conclusion reached is t h a t lack of cultivation, lack of proper pruning, absence of spraying a n d fumigation with insecticides are mainly responsible for t h e unusually b a d condition which exists among t h e trees, vines a n d shrubs i n t h e Selby “ Smoke Zone.” T h e indifference of certain farmers t o these conditions is illustrated b y t h e fact t h a t , during his investigations, Professor Doane volunteered t o advise t h e farmers free of charge as t o t h e proper methods for combating insects a n d t o supervise their a t t e m p t s , yet none of t h e m accepted his services or took a d v a n t a g e of t h e o p p o r t u n i t y t o i m prove existing conditions. SOIL INVESTIGATIONS
T h e problems presented t o t h e agronomic soil experts were:
Jan., 1915
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
I-Are the agronomic conditions of the “Smoke Zone” such as to conduce to high agricultural development? z-Does there exist in the “Smoke Zone” any soil trouble which is responsible for any poor condition of plant growth which may exist? 3-Has the soil of the “Smoke Zone” been polluted by materials deposited therein from smelter smoke? 4-If such pollution exists, is it of economic importance? May it influence the growth of crops or plants for good or for ill? T h e yield of crops in the area are below the average for areas in other sections of t h e state having the same climate. T h e poor quality of t h e soil a n d the poor agricultural practices are sufficient t o account for t h e existing b a d conditions as t o crops a n d crop yields. N o soil trouble exists, other t h a n t h e poor quality of t h e soil, t o which t h e existing conditions of plant growth can be traced. I n t h e m a t t e r of soil pollution, a n extensive investigation was conducted. Samples of soil were t a k e n from various portions of t h e area a n d subjected t o examination t o determine t h e presence of lead a n d arsenic. These metals were found t o be natural constituents of t h e soils of the “Smoke Zone” a n d the country surrounding the “Smoke Zone.” A slight increase in t h e lead a n d arsenic present in the soil was found in the area nearest t h e smelter, b u t this increase was shown t o be of no economic importance. Supplementing this work, t h e d a t a collected by Mr. Wells on the presence of lead a n d arsenic in t h e air before t h e installation of t h e roaster baghouse proved t h a t although lead a n d arsenic were present, t h e a m o u n t was unimportant from t h e point of view of soil contamination. E F F E C T OF SMELTER F U M E S O N HORSES
T h e veterinary survey included the identification of every horse a n d t h e enumeration of all t h e other important domestic animals within t h e Zone. T h e listing of the horses developed t h e fact t h a t 3 1 horses o u t of a total of 308 within t h e “Smoke Zone” were suspected as being of the type known as “roarers;” 1 2 of these 31 were diagnosed as “roarers,” t h e “roaring ” condition being brought about directly by the paralysis, either partial or complete, of certain muscles of t h e throat a n d neck, which causes improper functioning of t h e respiratory system, so t h a t under exercise t h e animal so affected breathes with a peculiar roaring sound. It was t h e opinion of t h e experts t h a t t h e condition of these roarers was due t o chronic lead poisoning a n d t h a t t h e animals h a d been injured b y smelter smoke. INSTALLATION
OF
BAGHOUSE
FOR
ELIMINATION
OF
VISIBLE S M O K E
Soon after beginning its investigations, the Commission came t o t h e conclusion t h a t a study of t h e a t mosphere of t h e “Smoke Zone” uncontaminated b y t h e visible element of t h e smoke of the Selby Smelter would be highly desirable. T h e Selby Smelting a n d Lead Co. were, thereupon, requested by t h e Commission t o take steps t o remove all solids from t h e smoke t h a t was being discharged from t h e plant. T h e Selby Company, with commendable promptness, began t h e erection of a baghouse, b y means of which t h e
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visible smoke from t h e roaster stack (the only source of visible smoke) could be eliminated. The Commission’s request was made October 25, 1913,a n d the installation of the baghouse was completed April I, 1914,a t a n expense t o t h e Selby Smelting and Lead Co. of approximately $35,000. I n order t h a t full information might be a t hand upon which t o base recommendations for the subsequent operation of the smelter, in the event t h a t a nuisance was found t o exist within the “Smoke Zone,” the Commission early undertook certain studies t o determine t h e possibility of eliminating t h e sulfur dioxide from the smoke of t h e plant before t h e latter is sent into the atmosphere. An investigation was conducted t o determine the possibility of operating t h e Dwight a n d Lloyd Sintering machines of t h e plant in such a manner as would allow the production of a gas with a sulfur dioxide content sufficiently high for its recovery as a by-product. As a result of this investigation, it was found t h a t b y a proper preparation of t h e charge a n d the recirculation of a part of the gases, t h a t 80 per cent of the total sulfur dioxide eliminated b y the machines can be concentrated in a volume containing 7.5 per cent sulfur dioxide. With this concentration i t is possible t o apply a commercial scheme for recovery by t h e production of sulfuric acid, liquid sulfur dioxide or sulfur. F I N D I N G S O F COMMISSION
From the personal investigations b y the Commission a n d from a study of t h e various reports presented, the Commission finds t h a t : I-The Smelter Company violated t h e injunction u p to April, 1914,with respect t o damage t o certain horses in t h e “Smoke Zone,” a n d t h a t this violation ceased when the roaster stack baghouse was installed. 11-The Smelter Company has not violated t h e injunction with respect t o disagreeable odor maintained in t h e “Smoke Zone,” nor with respect t o injury produced on crops or vegetation or on domestic animals through emitting sulfur dioxide into the atmosphere. 111-The Smelter Company will not violate the injunction if i t discharges less t h a n 80 tons of sulfur dioxide per 2 4 hours into the atmosphere, a n d cleans the smoke of its visible element. IV-The Smelter Company will not violate the injunction, if for purposes of cleaning or repairing the baghouse, visible smoke is discharged for periods not t o exceed a total of 48 hours in a n y one month. SELBYSMELTER COMMISSION 325 MONADNOCK BUILDING.SAN FRANCISCO
A TITRATION TABLE B y R. S. POTTERAND R. S. SNYDER Received October 17, 1914
I n t h e course of some work which was being carried on here a t one time, twelve different standard solutions were required a n d a space-saving disposition of these was necessary. The arrangement which has been found very practicable is shown in t h e accompanying illustration. Others might find something similar
