618
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
Dec. 14, 1916, 164; Geol. M a g . , 4 (19171, 93. 9-D. T.Jones and R. -’. Wheeler, “Composition of Coal,” J . Chem. Soc., 109 (1916), 767. 1 0 - D . R. Stuart, “Chemisrry of the Oil Shales,” “Oil Shales of the Lothians,” P a r t 3 . Scotland Geol. Sur. Mcms., 1912, 136. 11-C. Engler, “Formation of the Chief Constituents of Petroleum,” Petroleum, 7 (1912),399; C. A., 6 (1912), 1221. 12-H. M. Cadell and Grant Wilson, “Geology of the Oil Shale Fields, The Oil Shales of the Lothians,” Part 1. Scotland Geol. Sur. Mems., 1912, 1-97 13-Hardy W. Mansfield, “Oil Shales and Thrir Occurrence,” Petroleum Rev., 34 (1916), 159, 199. 14-Hardy W. Mansfield, “Oil Shales,” J . Inst. Petroleun: Tech. (London), 2 (1916), 162. 15--“Transvaal Oil-Shale Deposits,” M i n . World, 34 (1911), 74-76; Petroleum Rev., 24 (1911), 147-148; C. A , , 5 (1911), 783. W. McGrath, “Oil Shales of Newfoundland, ”Pelvoleurn Rev., 16-J. 33 (1915), 209; Can. M i n . J . , 36 (1915), 493. l7-“Bituminous Oil Shales in Canada,” M i n . World, 37 (1912). 202. 18-R. W. Ells, Can. Dept. Mines Joint Report on the Bituminous
Vol. 13, KO. 7
Oil Shales of h’ew Brunswick and Nova Scotia; also on the Oil Shale Industry of Scotland, 1909. 19-Dean E. Winchester, “Oil Shale in Northwestern Colorado and Adjacent Areas,” U. S. Geological Survey (Contributions t o Economic Geology), Bulletin, 641-F (1916), 139. 2G-G. E. Mitchell, “Billions of Barrels of Oil Locked up in Rocks,” Geog. Mcg., 33 (191S), 194. 21-V. C. Alderson, “The Oil Shale Industry,” 1920, 31. 22-G. H . Ashley, “Oil Resources of the Black Shales of the Eastern United States,” U. S. Geological Survey, Bulletin 641 (1917), 311. 23-Dean E. Winchester, “Oil Shales,” J . Frank. Iizst., 87 (1919), 689. 24-C. Bardwell, B. A. Berryman, T . B. Brighton, K. D. Kuhre, “Chemical Properties of Utah Hydrocarbons,” Trans. of Utah Acad. of Sci , 1 (1913), 78. 25-A. H . Allen, “On the Relative Proportions of Olefines in Shale and Petroleum Products,” Analjst, 6 (1881), 177-180. 26-C. Engler, “Formation of the Chief Constituents of Petroleum,“ Petroleum, 7 (1912), 399-403; C. A , , 6 (19121, 1221. 27-Herbert Abraham, “Asphalts and Allied Substances,” 1918, 57. H. McKee and E. E. Lyder, U. S. Pat., Application No. 28-R. 381,440.
Studies on the Toxicity of Wood Preservatives-XIX1~z By C. J. Humphrey, Ruth M. Fleming and E. Bateman LABORATORY OF FOREST PATHOLOGY, BUREAUO F
PLANT INDUSTRY, I N
Since the date of our last publication3 on this subject, petri-dish tests have been conducted on a number of wood preservatives. These preservatives have, in many instances, been prepared by the Section of Derived Products of the Forest Products Laboratory with the idea of throwing further light on the relation existing be ween their toxicity and chemical and physical properties. METHOD The petri-dish method used was essentially that described in former articles4 on this subject. The petri-dish cultures were placed in an incubator kept a t approximately 25” C., and records of the rate and nature of growth were made every week for 6 wks. For each set of concentrations a check culture, consisting of 17 cc. of agar medium plus 3 cc. of distilled water, was prepared. The killing point was always verified once, and sometimes twice. The fungus used was Fomes annosus Fr. This organism is a rapid wood destroyer and grows well on the medium used. The petri-dish method has been followed in all the toxicity tests conducted a t the Lab0ratory.j Other methods of test have been considered from time to time, such as the impregnation of wood or sawdust with varying dilutions of the preservatives, but these appear to offer no advantages over the petri-dish method, using an agar substrate, except possibly in the case of such substances as copper sulfate and zinc chloride, which may react with the agar medium. The petri-dish method has the following advantages over other laboratory methods considered: 1-It is simple and rapid. 2-It requires little space for carrying on a large number of simultaneous tests. 1 Received
March 14, 1921. Published by permission of the Secretary of Agriculture. 8 R . M. Fleming and C. J. Humphrey, THIS JOURNAL, 7 (1915), 662. 4 C. J. Humphrey and R. M. Fleming, Ibid., 6 (1914), l2d; see also U. S. Department of Agriculture, Bulletin 227 (1915). 6 T h e method has been improved from time t o time since t h e tests here recorded were made, from 3 to 5 yrs. ago. A shaking machine for mixing the agar and preservatives has been developed which is of particular advantage with the more difficultly miscible oils. Also, in t h e case of many of the oils, i t has been found that cooling the agar-preservative mixture on ice fixes the finely divided oil particles uniformly in the medium, constituting a decided improvement. Beef extract has been entirely eliminated, since it is of no particular value for the growth of the fungi and in some cases is a detriment, and since i t is objectionable on account of the combination of the proteins with certain of the preservatives. 2
COOPERATION
WITH THE
FOREST PRODUCTS LABORATORY, MADISON,WIS.
3-It permits of successive growth measurements of .the fungus to determine the retarding effect of the preservative on the organism, which data are essential in deriving mathematical equations to express the relation between toxicity and fungus growth. 4-It gives a more uniform mixture of preservative and substrate in many cases. 5-No organic solvent (diluting agent), such as alcohol, ether, etc., is necessary in order to secure the desired concentration.
In interpreting all laboratory tests on toxicity it should be kept in mind that they show only the relative antiseptic values of the preservatives and give an indication of the minimum amount necessary to prevent fungus growth. The commercial value of a preservative depends upon a number of factors, the two more important from the standpoint of decay prevention being (1) toxicity, and (2) permanence in the wood under service conditions. Under approved impregnation methods used commercially, in order to obtain the necessary penetration the antiseptic requirements are several times fulfilled by a good preservative, such as coaltar creosote, so that minor differences in toxicity would be overshadowed by the larger quantity of preservative introduced. RESULTSOF THE TESTS Table 1 gives a coniparison of the toxicity of beechwood creosote, both crude and distilled, and also a comparison between the phenolic and neutral portions of fractions of the same oil. TABLE TOXICITY OF CRUDEA N D DISTILLEDBEECHWOOD CREOSOTS A N D ITS NEUTRALA N D ACID PORTIONS Distillation Killing Point Limits between DESCRIPTION c. (Per cent) SOURCE Commercial beechwood 0 . 1 2 a n d O 24 creosote, Sample 3359 . . . Total distillate’ of above, Sample 3469 150°-2600 0 . 0 5 and 0 1 Distilled in laboratory Portion of total distillate soluble in KOH, consisting of phenolic bodies, Sample 3460 18O0-26O0O 0 2 5 and 0 . 0 6 Prepared in laboratory Neutral portion of 195O-20Oo fraction, insoluble in KOH 195°-2000 0 2 and 0 ;j Preoared in laboratorv Phenolic 1960-2qo‘orY2C;io,,f soluble in KOH 195°-2000 0.075 and 0 . 1 Prepared in laboratory 1 The chemical work involved in the preparation of the different fractious was done b the Section of Derived Products of the Forest Products Laboratory u n L r t h e direction of Dr. s.F. Acree. I n this connection see article
.
July, 1921
T H E JOC'RXAL OF IATDCSTRl.41, A X D EA'GINEERISG CHEMISTRY
Pi.*TB
I'LAIE 1
Fig. l-Fotnrr R ~ ~ S UODS 0,025 per cent conceniiaiioii 01 KOH-soluble poliios of bceuhwocd C r e ~ ~ o Ldistillate, r Snmple 3460: s l l r i G wks. Fig. 2--Fomer nmosiis on 0.05 per r e n t cumentratioo of K O H o l u b l r (phenolic) pmtiori 01 IY5'-20O" C . fraction 01 tufa1 distillate of lieechwoud CleOEOte:
6 wks.
Fis. a-Sanre on 0 075 ne.r cent eoncmirntion: G wks. RE.4-Same on 0.1 ner cent: G wks. Fig. 5-Fomrs annosi'l 011 1 p c i cent CDirrentlntioir of Crcsoil,Sampie R , XO.3'497; h wkr. Fig. ti-Smmr on 0.05 per cent concenlnlion of Cresoil, Sample D, No. 3391);G wkp.
Tlie total distillate is fully twice as toxic as the commercid oil, and tlie plienolic portion of t,he total distillate (Plate I, Fig. 1) is again twice as toxic as the total dist,illate. Comparing the plienolic portion (soluble in KOH) of the fraction whose boiling points were between 195' and 200"C., tlie phcnolio portion (Plate I, Figs. 2-4) is again much inma toxic than the neutral. In nddiiion to the above, fifteen fractions of the cominercial hecchwood creosote mere prepared for toxicit,y tests. These fractions xere taken every 5' C. from 180" i o 255" C. The results of thrse tests are given in Table 2. The killiiig points were generally checked in duplicate, hut this was not always an', as eiich killing point was more or less of a check on t,lic one of the next, higlicr or lower fraction. The tests sliov t,hat. as the I;)oiling point of the fractions increases there is n marked increase in toxicity up to 225" C. Above this point t,he toxicity of the fractions remained e_ " A Study
of
Commerrirl Beechwood
619
I1
c.
pig. I - - P ~ annosus ~ ~ S os, 0.25 per cent cosccniirtios of iso"-ls.i' fraction af beechwood creo~ote;alter 6 wks. Fie. 2-Same on 0.3 per ccnt: 8 wks. Fig 3-Fomra Bnnosus 01, 0.2 pcc cent cOncentritlon 01 185~-19O"C. frrciioii of beechwood creosote: G wkr. Fig. 4-Same on 0 25 per cent: 6 wks. Fig. 5--Fomc* DnnoSUE on 0.1 per cent concentra*ian o f 2 0 0 - " 2 0 5 ~ c . fiSiclioii of beechwood ciemou: 6 wkr. Pig. 8-Sanre 00 0.15 per cent: u wks.
coiistniit. This five-fold irierease in toxicity between the Tns,.*
2---r"xlc,TY o*
FY*FII
