Document O37KkOx00D6ynBnL3Ey5MbkRe

June 3, 1386 Dr. R. L. Shriner University of Illinois Department of Choaistry Urbans, Illinois Dear Dr. Shriner* Thanks very mash for your sots concerning It&rleating oil being used as an insecticide, It is ay opinion tint it -would taka quits s good deal of lead to kill a eow# certainly sell over ton grams. Four per oesxt lead is possible in the lubrieat- ing oil, although most of it is in the fora of solid particles which settle quite rapidly. Even on this basis "Bossy* most drink somewhere in the neighborhood of a half pint of lubricat ing oil to obtain a lethal dose of lead. This is & lot of oil for any oow. i- Deapite tits above remarks, I most certainly consider it very dangerous practice to use spent lubricating oils which nay contain lead. Sven if a lubricating oil did not contain lead, I am sure that any appreciable quantity taken internally will sheer decidedly toxie effects doe to the types cf organic aoids, aldohydaac, ketones and other oxidation products. Best regards. Very truly yours. Thco&s Midgley, Jr. (iny replies address to Worthington Ohio.)