October, 1925
INDUSTRIAL A N D ENGINEERING CHEMISTRY
water drain for a time by a sunken log. This shows Very well the ease with which the waters of the canal and lakes might have become contaminated if proper control had not been provided b y the army engineers. The data for June, “1922, indicate the effect of drainage resulting from winter rains and spring freshets. I n Figure 4 the logarithms of the parts per million of chlorine for the maximum and average conditions are plotted for the various depths at the different stations along the waterway. Table 111-Parts per Million Chlorine, S h o w i n g Maximum a n d M i n imum C o n d i t i o n s O b t a i n e d a t Various D e p t h s a n d Different Stations Date Depth in Feet--0 10 20 30 32 40 45 50 Station tested 3 Feh. 20, 1920 Oct. 21, 1921 244 310 2315 7800 9075 237 9 33 32.5 June 22, 1922 10 16 26 55 130 4 Feb. 20, 1920 16 198 360 3555 Oct. 21, 1921 193 June 22, 1922 6 8 13 600 15 16 14 5 Feh. 20, 1920 16 171 315 2920 Oct. 21, 1921 169 7 75 4 June 22, 1922 3 12 15 14 6 Feb. 20, 1920 9 137 135 2940 3125 Oct. 21, 1921 128 4 20 28 3 June 22, 1922 3 9 9 9 4149 5040 9 Feb. 20, 1920 7 Oct. 21, 1921 70 111 145 2875 4710 5830 Jxne 22, 1922 4 3 5 10 ‘420 3095 10 Feb. 20, 1920 3 3 3 3 3 1985 2.507 37 178 Oct. 21, 1921 36 4 4 3 3 June 22, 1922 3 11 Feb. 20, 1920 3 3 3 3 505 Oct. 21, 1921 6 14 173 3 3 3 June 22, 1922 3 3 12 Feb. 20, 1920 3 Oct. 21, 1921 3 3 3 June 22, 1922 3
1087
Rather peculiar results for maximum conditions a t depths of 20 feet and 30 feet and for average conditions at 30 feet are indicated by the curves in Figure 4 at Stations 3 and 4. The former, being nearer the locks, should show a greater degree of salinity, but much of data collected show t h a t Station 4 generally gave higher concentrations. This is probably the result of countercurrents. Conclusions
1-The concentration of the sea water in the Lake Washington Ship Canal is dependent upon (a)amount of rainfall, (b) number of lockages, (c) proper functioning of the salt water drain, and (d) methods of disposal of surplus water. 2-If the surplus waters are conducted as much as possible through the lock valves, the degree of salinity can be maintained a t a minimum far lower than if the surplus is permitted to run wholly over the spillways. 3-Greater efficiency could undoubtedly be obtained if the salt water basin mere enlarged in length and width or depth. 4-Lake Union serves as a secondary salt water basin and prerents the contamination of the water of Lake Washington. 5-Storage of some of the surplus water of the winter and spring months, to be used for drainage through the lock valves during the dry season, would aid materially in decreasing the salinity of the canal system. This could be accomplished b y raising the level of the system about one foot.
A Nonstratifying Carbon Disulfide Emulsion’Bz By Walter E. Fleming BCREAUO F ENTOMOLOGY. U. S. DEPARTMENT OF AGRICULTURE, RIVERTON, N. J.
ILUTE carbon disulfide emulsions are now used extensively to destroy the l a r w of the .Japanese beetle, Popillia japonica Yewm., in the soil about the roots of valuable plants. The concentration of the toxic agent in these emulsions must be carefully controlled in order to obtain the insecticidal action without seriously injuring the plants. I t has been the practice, therefore, to prepare the dilute emulsion for such plants by pouring a definite volume of a concentrated (70 per cent) emulsion into the necessary amount of water. Experience has shown that concentrated carbon disulfidesoap-water emulsions tend on standing to stratify into two or more layers of different carbon disulfide content, which must be agitated again to form homogeneous mixtures. Agitation causes these emulsions to foam and makes their measurement difficult. If the emulsion is not agitated until it becomes homogeneous, the dilution made from the heavier portion will have an excess amount of the toxic agent and is likely to injure the plant, whereas the dilution made from the lighter portion might not kill the insect. I n view of these results, experiments were begun to develop a nonstratifying concentrated carbon disulfide emulsion which could be readily measured in small quantities. The stratifying of the carbon disulfide-water emulsions is caused by the heavier specific gravity and the nonmiscibility of the carbon disulfide. The water of this concentrated emulsion 1
Received August 25, 1925. Contribution No. 1, Japanese Beetle Laboratory, Riverton, X. J
mas therefore replaced by certain organic liquids such as benzene, acetone, methanol, and ethyl alcohol, which are miscible with carbon disulfide. Many combinations of these compounds with carbon disulfide and potassium oleate were prepared and tested for their facility of dispersion in water. I t was found that a mixture of carbon disulfide, ethyl alcohol, and potassium oleate was the most satisfactory. Further experiments showed that the addition of refined cottonseed oil to the alcoholic carbon disulfide mixture aided the dispersion of the carbon disulfide when the mixture was diluted with water. I n the preparation of a liter of this alcoholic mixture, dissolve an excess of potassium hydroxide in alcohol, filter off the insoluble carbonate, and, after determining the hydroxide content of the filtrate by titration against a standard acid, add sufficient alcohol to obtain a concentration of 13.5 grams of potassium hydroxide per 193 cc. of alcohol. Pour 77 cc. of oleic acid into each 193 cc. of the potassium hydroxide and alcohol solution. Then add 700 cc. of carbon disulfide and 30 cc. of cottonseed oil to each 270 cc. of the oleic acid-alcoholic solution. The resulting carbon disulfide mixture is amber-colored, transparent, and homogeneous over a relatively long period (at least six months). It is easily measured in small quantities and mixes well with water. It must be diluted initially with a n equal volume of water before mixing with the larger quantity of water, used in the insecticidal treatment, in order t o obtain a good dispersion of t h e carbon disulfide.
