INDUSTRIAL AND ENGINEERING CHEMISTRY
28
Vol. 20, No. 1
fact that nitric acid in sulfur is also effective. Moreover, a safeguard which should be employed in using all sulfur in more recent experiments other oxidizing agents in sulfur, dusts, whether oxidized or not. The dusts should be kept which have been effective and which in themselves have no dry and always stored away from sources of moisture. fungicidal or germicidal value, have been found. Most conThe use of a stable chlorine compound, such as chloramine clusive, however, is an experiment in which potassium per- T, holds some promise of being effective under conditions in manganate in Celite, a non-sulfur carrier with a neutral which the oxidized sulfur mixture would not be advantageous. reaction, has had a very slight effect in reducing the disease. Owing to the rainfall conditions in many of the caneThis and experiments with additional oxidizing agents in growing localities in the Hawaiian Islands, the use of these sulfur will be reported more completely in a subsequent fungicide preparations is still not an economic plantation paper. practice. However, with still further improvements the Sulfur containing oxidizing agents is, of course, to be care- method may become feasible. I n the meantime these results fully protected from a source of ignition. At the time of indicate that these preparations may be of value for use writing more than 30 tons of sulfur plus 1 per cent potassium against other diseases on other host plants, and the writers permanganate have been applied with no difficulties. A few hope that other investigators will carry further these initial precautions have been taken, as follows: The outlet tube of attempts to develop new and more effective fungicidal dusts. the motor-driven dusting machines, in which considerable The writers have applied for a patent on the use of oxidizing static electricity is sometimes generated by the friction of the agents with sulfur as a disinfectant and fungicide; however, passing dust particles, is grounded with a steel chain which is any royalties will be employed for the furtherance of reallowed to drag during the operation of the duster. This is search.
Experiments in Wood Preservation’ VI-Recent Laboratory Work Leo Patrick Curtin and William Thordarson ENGISEERIKG LABORATORIES, WESTERN UNIONTELEGRAPH CO.,NEW YORK,N. Y.
Toxicity toward Fomes Annosus Of Various Preservative Materials
Toxicity data not previously reported are given, also a table showing the “killing points” of the various inorganic preservatives experimented with in this research. Twelve additional fungi have been studied; all of these evolved sufficient acid to convert sodium alizarin sulfonate to the free sulfonic acid (PH 51, and seven gave an acid reaction with methyl orange (pH 3). The toxicity of zinc meta-arsenite in powder form toward fourteen wood-rotting fungi has also been studied.
ANY of the data on t o x i c i t y have been given in the preceding papers of this series. Some a d d i t i o n a l determinations, made in the Western Union Laboratories, are given below. The test fungus was Fomes annosus and the “killing point,’’ the lowest concentration which completely inhibits growth, is italicized. This was determined 4 weeks after the cultures were made. All figures are percentages by weight. The nutrient gel contained, in addition to the preservative, 2.5 per cent malt sirup and 1.5 per cent agar, An asterisk indicates an independent duplication of the culture.
M
PRESERVATIVE: 2,4-Dinitrophenol. N o growth 0.008* 0.009 Growth 0.007 0,006
0.010*
0.006
PRESERVATIVE: Texas petroleum, density at 38’ C., 0.905. Growth 40.0 30.0 20.0 10.0 5.0
There was rapid, though delicate, growth in the culture containing 40 per cent petroleum. It is not practicable to make cultures containing petroleum in higher concentrations; in these cases there was considerable free oil on the surfaces. 0.30 0.08
0.04
PRBSERVATIVE: Copper sulfate pentahydrate. 0.16 No growth 0.15 0.10* 0.125 Growth
0.40 0.05
1
Received November 4, 1927.
Copper fluoride. Precipitated in gel containing copf ” ~ t S ~ ~ $ ~ m b & $ ~ Of ~ ~equiva.on No growth 00.08 .06 0.02 0.10* Growth
Very slight growth a t 0.06. Copper fluoride, powder. No growth 0.097 Growth 0.05
0.311
Copper ortho-arsenite, Scheele’s green, precipitated in gel. PRESERVATIVE: N o growth 0.04** 0.05 0.10 Growth 0.03 0.02 0.01
Negligible growth a t 0.03, very feeble and discolored growth a t 0.02. I n powder form, complete inhibition a t 0.10 per cent.
0.001
The greenish yellow color of this material is clearly evident at concentrations of one-tenth the killing dose or 8 p. p. m.
PRESERVATIVE: Orthoboric acid. No growth 0.15 Growth 0.10
Feeble, discolored growth at the 0.125 concentrations, which did not start until the fourth week. Good growth at 0.05.
Copper aceto-arsenite, Paris green, powder. PRESERVATIVE: No growth 0.04 0.10 Growth 0.03 0.01
The 0.03 culture showed growth of 2 mm. radial increase in 4 weeks. PRESERVATIVE : hfercuric chloride. N o growth 0.015** Growth 0.010*
0.020* O.M)75
0.030 0.0050
Delicate but healthy growth at 0.010. Vigorous growth at 0.0050. PRESERVATIVE : Sodium monohydrogen arsenite. 0.10 No growth 0.025** 0.020** 0.015* Growth
0.010*
Growth sickly and discolored at 0.010. PRESERVATIVE: Arsenious oxide. No growth 0.0150*** 0.0200* (0.010***) 0.0100* 0.0080* 0.0060 0.0050* Growth
INDUSTRIAL A N D ENGINEERING CHEMISTRY
January, 1928
Four cultures a t 0.010 failed to grow. Growth a t 0.005 feeble and brown in color. Corresponding culture with mercuric chloride permitted a white, healthy growth. I n making cultures with arsenious oxide, misleading results are usually obtained by adding the preservative in powder form. Because of the non-wetting properties of the crystals, solution takes place in a very incomplete manner. A solution of arsenious oxide should be prepared by boiling, the undissolved residue filtered out, and a sample of the filtrate analyzed for arsenic content. The solution, properly diluted, may be added to double-strength nutrient. Table I gives a list of inorganic substances experimented with and their killing points toward Fomes annosus. Information in regard to organic preservatives is given in this and the fourth paper2 of the series. T a b l e I-Concentration
of Preservative W h i c h T o t a l l y I n h i b i t s Fomea a n n o ~ u s FORMULA
PRESERVATIVE Barium chloride Barium carbonate Strontium chloride Strontium carbonate Calcium chloride Calcium carbonate Zinc chloride Zinc oxychloride Zinc hydroxide Zinc meta-arsenite (powder) Boric acid Copper sulfate Copper fluoride Copper ortho-arsenite Copper ortho-arsenite (powder) Copper aceto-arsenite (powder) Mircuric chloride Sodium carbonate Sodium monohydrogen arsenite Arsenious oxide ~
BaCh BaCOa SrClz SrCO3 CaCIz CaC03 ZnClz Zn(0H)CI Zn(0H)z Zn(As0z)z H - B_G_ CuS04.5HzO CuFz Cua(As03)~.2HzO Cua(AsOs)z2HzO Cu~(CHaCOOh(As0z)s HgClz NaKOs NazHAsOa Aslo3
“KILLIRG POINT” Per Cent of Preserualwe 11.0 0.625 10.0 3.0 8.0 1.50 0.35 0.30 0.30 0.10 0.150 0.150 0.080 0.040 0.10 0.040 0.015 0.33 0,025 0.015
Further Experiments with Wood-Rotting Fungi
The first paper3 of this series describes tests with certain wood-rotting fungi which showed that the growth of such organisms is attended by immediate production of acid. These fungi were Fomes annosus, Lentinus lepideus, Lenzites sepiaria, Polyphorus pilotae, and Polyphorus sulphureus. All cultures reacted acidic to sodium alizarin sulfonate and neutral to methyl orange, indicating that the concentration of the hydrogen ion evolved was pH 5 to pH 4.8. Certain mold fungi-for example, Rhizopus nigricans-evolved substances acidic to methyl orange, indicating a concentration of pH 3. For the purpose of further investigating the reactions of fungi, tests were made with twelve additional species, all of economic importance in the destruction of wood. Cul2 J
I n d . Eng. Chem., 19, 1231 (1927). Ibid., 19, 878 (1927).
FUNGUS Polyphorus anceps Polyphorus anceps Polyphorus schweinitzii Polyphorus schweinitzii Poria incrassata Poria incrassata Poria subacida Poria subacida Slereum subpilealum Slereum subpilealum Trameles p i n i Trameles pini Polyphorus belulinus Polyphorus belulinus Polyslicfus versicolor Polrsfictus versicolor Coniophora cerebella Coniophora cerebella Merulius lachrymans Mcrulius lachrymans Dacdalia quercina Dacdalia quercina Leneiles lrabea Lenealrs trabca
29
tures were made in quadruplicate by the standard agarmalt sirup formula, one-half being dyed dark red with sodium alizarin sulfonate while the remainder was colored orange-yellow with methyl orange. The dishes of nutrient gel were then inoculated under aseptic conditions with pure cultures of the various fungi listed in Table 11. These cultures were obtained from the Forest Products Laboratory, Madison, Wis., through the courtesy of Dr. Audrey Richards. All the fungi evolved sufficient acid to give a reaction with sodium alizarin sulfonate, indicating acid concentration of approximately pH 5. Stereurn subpileatum and Poria subacida showed faintly acid to methyl orange, corresponding to pH 4. Poria incrassata, Polyphorus betulinus, Coniophora cerebella, Merulius lachrymans, and Daedalia quercina: gave a strong acid reaction with methyl orange, indicating a hydrogen-ion concentration of approximately pH 3. Merulius lachrymans appeared to produce the most acid; the methyl orange cultures were turned red to a distance of 10 111111. beyond the visible growth of the fungus. This fungus is responsible for large economic losses in the destruction of timber by “dry rot.” Poria incrassata and Coniophora cerebella are also important dry-rot fungi. Coniophora cerebella, in the methyl orange cultures, first turned the indicator red and then destroyed it. When the fungus had increased to a diameter of 5 cm., it appeared by transmitted light as a white disk 4 em. in diameter surrounded by a red rim about 1 cm. across, this in turn bordered by a wider orange-yellow band. The white disk represented nutrient in which the methyl orange had been acidified and destroyed, the red portion where it had been acidified but not yet destroyed, and the orange-yellow zone nutrient which had not been attacked. As the boundary lines of the colors were fairly sharp, the appearance of the culture was most striking. Toxicity of Zinc Meta-Arsenite
This preservative is the most promising, from a practical point of view, of all the materials tested in this research. Its principal advantage, as compared with the arsenites of copper, is that it does not corrode iron and may be used in standard pressure-treating equipment. As compared with water-soluble preservatives, exhaustive tests have shown that it does not increase the electrical conductivity of wood, this being of importance to railroads and telephone and telegraph companies. Wood containing arsenites of zinc and copper has also remained unattacked by insects or fungi in the drastic field tests conducted by the Telegraph Company in the last two and one-half years and, unlike wood containing other water-borne preservatives, has shown little loss of preservative when exposed to the weather.
T a b l e II- Acidic R e a c t i o n s of Wood-Rotting Fungi SOURCE INDICATOR ORIGINAL(BASIC)COLOR FINAL (ACIDIC)COLOR White spruce Sodium alizarin sulfonate Dark red Greenish yellow White spruce Methyl orange Orange-yellow N o change Douglas fir Sodium alizarin sulfonate Dark red Greenish yellow Douglas fir Methyl orange Orange-yellow KOchange Southern yellow pine Sodium alizarin sulfonate Dark red Greenish yellow Southern yellow pine Methyl orange Orange-yellow Rose-red Balsam fir Sodium alizarin sulfonate Dark red Greenish yellow Balsam fir Methyl orange Orange-yellow Orange-red White oak Sodium alizarin sulfonate Dark red Greenish yellow White oak Methyl orange Orange-yellow Orange-red Hemlock Sodium alizarin sulfonate Dark red Greenish yellow Hemlock Methyl orange Orange-yellow No change Birch Sodium alizarin sulfonate Dark red Greenish yellow Birch Methyl orange Orange-yellow Rose-red Beech Sodium alizarin sulfonate Dark red Greenish yellow Beech Methyl orange Orange-yellow N o change Sodium alizarin sulfonate Dark red Greenish ye!low Methyl orange Orange-yellow Rose-red Sodium alizarin sulfonate Dark red Greenish yellow Methyl orange Orange-yellow Rose r ed Oak Sodium alizarin sulfonate Dark red Greenish yellow Oak Methyl orange Orange-yellow Rose-red Western red cedar Sodium alizarin sulfonate Dark red Greenish yellow Western red cedar Methyl orange Orange-yellow No change
-
INDUSTRIAL AND ENGINEERING CHEMISTRY
30
The toxicity of zinc meta-arsenite has been studied in the case of Fornes annosus, and it was thought desirable to extend these tests to the other fungi which were available, Some of these had not been used for experimental work for several months and it was found that the pure cultures of Lentinus lepideus, Lenzites sepiaria, and Polyphorus pilotae were dead. The others were in good condition, however, and were used in the toxicity tests, the details of which are given in Table 111. The cultures were made with zinc meta-arsenite in powder form dispersed through the gel, as any attempt to precipitate the preservative in situ would probably result in the presence of a small quantity of free arsenious oxide in the culture. This method is unfair to the preservative as uniform dispersion of the particles of powder is very difficult to attain. The gel is, of course, non-toxic between the particles. Wood treated with zinc and copper arsenites shows, after seasoning, a very effective distribution of preservative. Microtome sections of yellow pine containing copper arsenite were stained with dilute potassium ferrocyanide and examined at 1500 diameters magnification. Untreated zones showed no color with the reagent while those parts containing copper were colored pink to mahogany. Photomicrographs showed heavy deposits of preservative in the medullary rays and resin ducts where fungous attack was most severe and lighter uniform deposits in the cells and cell walls. Microscopic studies on wood treated with zinc meta-arsenite indicate a distribution similar to that observed in the case of copper arsenite. We have found no stain which colors the crystals so effectively as ferrocyanide on copper. While the distribution of preservative in the gel is by no means comparable with that actually attained in wood, the tests may be of value if the shortcomings of the method are borne in mind. Table I11 shows the effect of powdered zinc meta-arsenite on the various fungi. A (-) indicates no culture of the fungus a t the given concentration of preservative. If there could be obtained a distribution of preservative in nutrient gel equal to that in wood treated under commercial conditions, it is believed that all the fungi listed in Table I11 would be totally inhibited at 0.10 per cent and some of them as low as 0.010 per cent of this preservative. It is interesting to note that the dry-rot fungi which showed sharply acid to methyl orange were also very sensitive to zinc meta-arsenite. of Powdered Zinc Meta-Arsenite toward Various Funei ‘URE AND CONCENTRATION OF Zn(As0z)z IN CULT FUNGUS GROWTHO F FUNGUS 0.00% 0 . 3 0 % 0.10% 0.06% 0.02% Fomes annosus None Feeble Moderate Good Moderate Good h’one Feeble Feeble Polyphorus anceps Polyphorus schumeinilzii None None Moderate Good Feeble Feeble Good &-one None Poria incrassala Moderate Good None Feeble Feeble Poria subacida Good None Feeble Moderate Good Steveum subpilealum None None None Good Trametes p i n i None None Feeble Good Polyphorus befulinus h’one Feeble Moderate Good Polysficlus versicolor None None None Good Coniophora cerebella Good h-one Moderate Feeble Merulius lachrymans Good None None Feeble Feeble Daedalia qucrcina Good None Feeble Moderate Good Lenziles lrabea None Feeble Polyphorus sulphureus
creosoted wood completely inhibited Fomes annosw and 4.49 grams of wood treated with zinc meta-arsenite also prevented growth of the fungus. The creosoted wood had been originally impregnated with 419 kg. per cubic meter (27 pounds per cubic foot) of grade No. 1 creosote while the wood containing zinc meta-arsenite was treated with 10.5 kg. per cubic meter (0.66 pound per cubic foot) of that preservative. It seemed desirable to test the resistance of the weathered wood containing zinc meta-arsenite against other fungi; therefore additional cultures of this type were prepared. The cultures contained 1.301, 2.784,4.488, and 6.570 grams of wood with enough agar-malt sirup gel to make the total weight 20 grams. These contained, in the wood, 0.1, 0.2, 0.3, and 0.4 per cent zinc meta-arsenite based on the total weight of the culture. The cultures were next inoculated with the fungi under test. Table I V lists the fungi and the results of the test. It shows that wood containing zinc meta-arsenite which has been cut into small pieces and exposed to the weather for 10 months has very high resistance to every one of this collection of rotproducing organisms. The wood is not only unattacked itself but is able to prevent fungous growth in the non-toxic nutrient gel with which i t is mixed. Table IV-Toxicity
-
-
-
-
-
I n a previous paper of this series4 toxicity tests are described in which wood impregnated with various preservatives is finely ground, mixed with nutrient gel, and inoculated with a fungus. It was found, with sawdust made from treated wood which had been exposed in small pieces to the action of the weather for 10 months, that the zinc meta-arsenite retained its high toxicity while creosoted wood had lost most of its toxicity and zinc chloride-treated wood actually permitted fungous attack. For example, 20-gram cultures containing 4.51 grams of 2 n d . Eng. Chem., 19,1343 ( 1 9 2 7 ) .
of W o o d Impregnated w i t h Zinc Meta-Arsenite toward Fungi CONCENTRATION OF Zn(As0dz AND GROWTH OF FUNGUS 0.4% 0.2% 0.1% 0.0% None Feeble Feeble Good None Feeble Feeble Good None None None Good None Feeble None Good None None Feeble Good None None Feeble Good None None Feeble Good None None None Good None Feeble Feeble Gocd None Feeble Good None None None None Good None None Good Good Ncne Feeble Good hTone None None Good None
FUNGUS Fomes annosus Polyphorus anceps Polyphorus schweinilzii Poria incrassata Poria subacida Slereum subpileotum Trametes pini Polyphorus belulinus Polystictus versicolor ConioDhota cerebella Merulius lachrymans Daedalia quercino Lenziley lrabea Polyphorus sulphureus
A Cheap and Accurate Metal Scale for Scientific Instruments’ David Crowther and J. J. Willaman UNIVERSITY OF MINNESOTA, ST. PAUL, MI“.
Table 111-Toxicity
I
Vol. 20, No. 1
HE writers recently had occasion to alter the scale on a color grader used for honey and sirups. The method adopted was to make a “positive” zinc etching of the desired scale and attach it to the instrument in place of the original. The scheme apparently should have wide application and, although the idea undoubtedly is not new, it does not appear to be generally known. An ink drawing is made two or three times as large a s the desired scale. The drawing is sent to the print shop with instructions as to the exact size of the reproduced scale. Instead of the usual reversed etching, a “positive” is made. The characters of the scale stand out in relief, the accuracy is the same as the original drawing, the scale is durable, and the cost is negligible compared with an etching or an engraved scale. 1
Received November 21, 1927. ~
Calendar of Meetings American Chemical Society-75th Meeting, St. Louis, Mo., April 16 to 20, 1928. American Electrochemical Society-Hotel Stratfield, Bridgeport, Conn., April 26 to 28, 1928.
