Document 71QpnBb5e1Xwbek1QJgbLp3eg

January 29 1931 Mr* Thomas S. Midgley, Worthington Ohio. Dear Midgj I have waited a few days to give you the infor mation about our last experiments on CClPrCClF because the animals last exposed were ill and I wanted to see what the outcome would be* On January 17 a guinea pig was exposed to ap proximately 15# concentration for fifty minutes. Very sat isfactory anaesthesia was produced the animal being in deep anaesthesia in about five minutes* He continued thus until the end of the exposure. Recovery took place in about five minutes, although after two hours the animal did not look entirely well. From this time on his condition became worse, and he died at the end of two days. Autopsy showed an acute edema of the lungs, a dilated heart, and edema and degeneration <St the liver. On January 24 three other animis were exposed, one to 9# concentration, another to a 12 concentration, and the other to a 5.8# concentra tion. The first was exposed thirty-nine minutes, the second thirty mimitea, and the last one hour. The 9# concentration produces a fairly satisfactory anaesthesia, but takes a lit tle longer period than 12# obviously. It allows an excita tion period of almost ten minutas. The 5-6# concentration does not produce anaesthesia at any time. The animal be comes somewhat dopey and occasionally breathes a little ir regularly, but generally speaking is scarcely effected by this concentration for a period of an hour. The concentra tion capable of producing anaesthesia is, therefore, some where between 6 and 9#, which is close enough, I believe, for all practical purposes. The first two animalB became ill after two to three hours following their exposure. One died on th next day and the other died the following day, with the same pathological findings as previously described. The animal exposed to 5.8# concentration for an hour became ill, and is still ill, but haB not succumbed. In any case he has been very dangerously near the edge. From these observations it seems reasonably clear that this material will not be satisfactory for anaesthetic purposes. Evidently some hydrolysis or some other chemical reaction produces in the tissues a toxle com- Its- 1 00 205 *2 pound which impairs the circulation and produces an edema of the lungs and the other tissues* The effect Is very much like that obtained when ethylene dibromide or ethyl ene chlorbifoaide is used, except that the latter two com pounds are very much more toxic initially. This is a bit disappointing, and unless there are still certain impuri ties in this compound to account for its toxicity, I am afraid it is out. Best regards to yourself and family. Sincerely, RAK:BJ / i 1 00206