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cleus controls the oxidation of the cell, but that the nucleolus enables the diseased cell to obtain nutrition a t the expense of the normal cell. The degree of malignancy appears to depend on the profundity of the changes in the nucleus and nucleolus of the cancer cells as compared with the normal cells of the same tissue. The more nearly the diseased cell reembles the normal cell, the lower the grade of malignancy. The establishment of this fact enabled the method of immediate diagnosis by microscopic examination of the frozen section to be developed by Wilson, MacCarty, and Broders, which is one of the greatest gifts that has been made to modern surgery. By means of microscopic examination of the frozen section it can be determined within two minutes whether or not the disease is cancer and also the degree of malignancy of the disease, so that the surgeon can act accordingly during the progress of the operation. It is interesting in this connection that keratin, which is a highly sulfurized substance, is sometimes found in cancerous tumors, usually in the form of a hyalin compound which indicates reduction of the malignancy. Demonstration of the catalytic action of certain sulfur compounds in the control of oxidation may explain a chemical phase of cancer development. Carrell, in his beautiful experiments in which he compares normal fibroblastic tissue, which he has had growing in a glass chamber for fifteen years, with growing fibroblastic tissue from
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the cancer of f o d s , shows that the malignant fibroblastic tissue grows more rapidly and that the growth is surrounded in its advance by an acid medium. Here may be drawn a comparison between fowl cancer and the crowngall cancer of plants, on which the late Erwin Smith contributed some of the most interesting data extant on the study of cancer. Warburg, in his valuable research on cancer, pointed out its extraordinary glycogenic action, but noted that there is no corresponding increase of respiratory carbon dioxide. He believes that much of the abnormal power of cancer cells may be due to fermentation, such as occurs normally in plants -for example, the action of yeasts. Only 10 per cent of the general population suffers from cancer. We may assume that this incidence is not accidental, but that 90 per cent of the people are more or less immune to the cause or causes of the disease. Perhaps methods may be developed by chemical research that will establish effective control of the 10 per cent with this disease, comparable to the methods by which modern medicine now controls deficiency, hereditary, and infectious diseases. Life is largely a matter of chemistry. The advancement of medical science began with those things which could be seen with the eye, or the eye aided by the microscope, and has now progressed into the ultra-microscopic field of chemistry. In its modern conception, therefore, medicine has become a branch of applied chemistry.
Some Fumigation Tests with Ethylene DichlorideCarbon Tetrachloride Mixture' L. F. Hoyt LARKINCo., INC.,BUFFALO, N. Y.
N E R fumigant consisting of 3 volumes of ethylene dichloride to 1 volume of carbon tetrachloride was recently reported by Cotton and Roark2 to be very effective against stored-product insects of the types which attack clothing and furniture upholstery as well as grain beetles, weevils, and moths. It has the advantages of being cheap, non-explosive, non-injurious to metals and textiles, and according to Cotton and Roark, unless breathed in high concentrations for a protracted period of time, no harmful results may be feared in working with this mixture. It is considered by these authors to be five times as toxic as carbon tetrachloride alone. Cotton and Roark recommend the use of 14 pounds or 5 quarts of the mixture per 1000 cubic feet for a 24-hour period at temperatures of 65" F. or over as giving satisfactory results in the gas-tight chamber of approximately 500 cubic foot capacity in which all their experiments were made. An insect infestation in stored feed required fumigation and this new fumigant was used. Fumigations were carried out in a room of 8000 cubic foot capacity and in a 500 cubic foot gas-tight furniture vault of the same type as that used by Cotton and Roark. The fumigant, consisting of a mixture of 3 volumes ethylene dichloride to 1 volume carbon tetrachloride as supplied by the Carbide and Carbon Chemicals Corporation, is a water-white liquid with an odor similar to that of chloroform. It has a specific gravity of 1.32 a t 60 F. and weighs 11pounds per gallon.
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1 Presented at the Regional Meeting of the Northern New York Sections of the American Chemical Society, Ithaca, N. Y.,December 9, 1927. * J . Econ. Enlomol., 20, 636 (1927).
Tests in Gas-Tight Furniture Fumigation Vault (8 by 10 by 6 feet) with Metal Walls
A room of the same type used by Cotton and Roark was available for a preliminary fumigation test. The material fumigated consisted of 100-pound bags of raw shelled peanuts slightly infested with Indian meal moth (Plodia interpunttella) and a piece of upholstered furniture on which were feeding live larvae of the clothes moth (Tineola biselliella). I n addition small portions of flour heavily infested with the flour beetle (Tribolium confusum) were planted in the room, as follows: 20-gram portion, in cloth bag, laid on top of furniture 20-gram portion, in cloth bag, placed between bags of peanuts 20-gram portion, in cloth bag, buried below surface of pastry flour in small paper sack 5-gram portion, in sealed manila envelop, placed between bags of peanuts 5-gram portion, in sealed manila envelop, placed between portion of the upholstery of furniture The room was closed and warmed to 82" F. Then 7 pounds (2.5 quarts) of the ethylene dichloridecarbon tetrachloride
mixture were poured into the trough near the top of the vault and the temperature of 82" F. was maintained for 24 hours The vault was then opened, purposely without previous ventilation; the odor of the fumigant and its effect on the eyes were so great that it was impossible to enter the vault until it had been properly ventilated. Not a single live insect could be found, a 100 per cent kill having been obtained of all control insects and of those infesting the fumigated material. A comparative test in the same fumigating vault with
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powdered Calcyanide had given similar results. One pound of the powder was used, the duration of fumigation being 24 hours at 75" to 80" F., and flour beetles well buried in overstuffed furniture had all been killed. Experiments i n an 8000-Cubic Foot R o o m
The room used as a fumigating chamber was approximately 24 by 30 by 12 feet, rated a t 8000 cubic feet capacity. The walls were brick and concrete; ceiling reenforced concrete; wood floor laid on cinders, over concrete, and walk and ceiling were whitewashed. The room had one door, 7 by 4 feet, and an opening, 2 by l l / z feet, 8 feet above the floor into a ventilating shaft. This opening was closed with a hinged cover which could be opened by a cord outside the room. The room was also equipped with a wall radiator, a 15-inch oscillating electric fan placed near the radiator, and a recording thermometer. The material fumigated was wheat germ infested with the confused flour beetle (Tribolium confusum) and to a lesser extent with the Mediterranean flour moth (Ephtstia kuehniella). The feed, in 100-pound bags, was so piled that the bags stood on end, one high only, with small air spaces between the bags. Piled in this way the room held approximately 320 bags. TEST1-The temperature of the feed when placed in the room was 60" F.; the temperature of feed in center of the bags when the room was opened 23 hours' after fumigation started was 70" F.; and the air temperatures as recorded by the thermometer were as follows: P.M. 60' F.; steam heat turned on radiator P.M. 90' F.;fumigant distributed over baas a t this time 11 P.M. 100° F. 9 A . M . 11OoF.
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110' F.; room opened, heat shut off,fan stopped
~ P . Y .70'F.
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The dosage of fumigant used was 10 gallons or 110 pounds, equivalent to approximately 14 pounds per 1000 cubic feet, splashed over the bags with the aid of dippers. Flour heavily infested with Tribolium, both adults and larvae, containing an average of 205 adult beetles and 450 larvae in 200 grams, and confined in 200-gram quantities in tightly woven cotton-cloth bags, had been buried 6 inches below the surface in two of the bags of feed. When examined after the fumigation (23 hours after release of fumigant) very few of the beetles or larvae appeared to have been affected. The flour and insects were placed in loosely stoppered jars a t 70" F. and when examined about 16 hours later all the adult beetles were dead and only a few of the larvae were alive. These live larvae all died within 3 days. A few moth larvae, still alive but in a very sluggish condition, were found on the feed after fumigation, but all the adult moths and flour beetles found, as well as most of the moth larvae, were dead. When the room was opened, without ventilating, the odor of the fumigant was very slight. It was possible to enter and remain in the room without discomfort. This test brought out three points often overlooked in practical fumigation. There is a big difference between a real gas-tight vault and an ordinary "tight" room as regards retention of the fumigant. The 8000-cubic foot room used Kas of better than average construction for fumigating purposes; yet the fumigant had largely disappeared by diffusion or absorption or otherwke within 24 hours, whereas in the 500-cubic foot gas-tight vault the concentration of fumigant a t the end of 24 hours appeared to be practically undiminished and unbearable to breathe or enter into. It is difficult to warm a material like feed in 100-pound bags, if received in a cold condition, to a temperature at which a fumigant is effective. In this case the temperature
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of the feed in the center of the bags was raised only 10" F., from 60' to 70" F., while the air of the room, circulated by a fan, was maintained at a temperature of 30" to 40" F. above that of the feed for 23 hours. Insects may be poisoned beyond recovery by a fumigant and yet appear almost normal when first taken out of the fumigating chamber. This delayed kill has been repeatedly observed by the author in fumigation tests ranging from a 1-gallon container to a 1/4 million-cubic foot room with several fumigants including chloropicrin, but not, however, with hydrocyanic acid. TEST2-Same room; same feed. The dosage was increased to 12 gallons, equivalent to 16*/2 pounds per 1000 cubic feet. The temperature of the room and feed at start was 62' F. About 24 hours after fumigation started the room was entered (without masks and without discomfort; odor of gas scarcely could be detected), The air temperature was then 100" F.; the temperature of the feed in the center of the bags was 70" F. The room was again closed, heat and fan being left on. At the end of 40 hours the room was opened; the air temperature was 110" F.; the temperature of feed in centers was only 76" F. Control insects had been placed in the room as follows: (a) Tribolium adults and larvae in flour, in tight cloth bags placed on floor between bags of feed. Insects all dead when examined 40 hours after fumigation started. ( b ) Same infested flour as above enclosed in loose mesh cotton cloth and buried 6 inches below the surface in a bag of feed. Most of insects dead after 40 hours; those alive were very sluggish and died within 2 to 3 days.
S u m m a r y of Results a n d Conclusion
The new fumigating mixture of ethylene dichloride (3 volumes) and carbon tetrachloride (1 volume) advocated by Cotton and Roark gave 100 per cent kill of all insects present when used in a gas-tight vault a t the rate of 14 pounds per 1000 cubic feet for 24 hours a t 82" F. Tests made in an 8000-cubic foot room on feed infested with flour beetles and moths using a dosage of 14 and 16l/2 pounds per 1000 cubic feet for %-hour periods gave satisfactory results. Owing to diffusion of the fumigant and to the difficulty of raising the temperature of the feed during the 24-hour fumigation, a 100 per cent kill was not immediately obtained, but the insects which survived were so poisoned by the fumigant that they all died within the following 3 days. Owing to its low cost, ease, and comparative safety of application, and easy removal following fumigation, coupled with its satisfactory killing effect on insects when used in a dosage of 14 pounds per 1000 cubic feet for 24 hours a t 70" F. or higher, this new non-burnable, ethylene dichloridecarbon tetrachloride mixture appears to be a valuable, safe fumigant.
Calendar of Meetings Hereafter the Calendar of Meetings will be found in the AND ENGINEERING CHEMISTRY. News Edition of INDUSTRIAL American Chemical Society-i6th Meeting, Swampscott, Mass., September 10 t o 14, 1928. 8th Midwest Regional Meeting-Minneapolis, Minn., June 7 t o 9, 1928. Pacific Intersectional Meeting-Pomona College, Calif ., June 13 to 16, 1928. Division of Colloid Chemistry, 6th National Colloid Symposium -Toronto. Canada. Tune 14 to 16. 1928. Institute of ChemistrylNorthwestern University, Evanston, Ill., July 23 to August 18, 1928. American Oil Chemists Societv-New Orleans, La., May 14 and 15, 1928. American Association of Cereal Chemists-Minneapolis, Minn., June 4 t o 9, 1928.
