"This report covers treating plant runs Nos. 18 and 19, made September 24 to 26, 1951, in which a heavy and a light naphtha produced by recycle cracking visbroken N-T-U crude shale oil were treated. The stocks were produced from cracking run No. .39 by splitting the gasoline fraction into a light and heavy naphtha in the stabilizer column. The primary objective of the runs was to obtain yields and product qualities for economic studies on treating these charge stocks. The secondary objective was to determine if chemical requirements could be reduced by acid treating only the heavy naphtha and washing the light naphtha with caustic soda as it was produced in the cracking operation."