Document 7pbd0YGq4j8eEMV1vdobRR7j

NEWMONT MINING CORPORATION HEW YORK, NEW YORK 001S796 O New York 22, New York Dear Mr. Volkman: I am sorry that your people at Tsumeb did not have a full understanding of the purport of my letter of August 6th. This was my fault, it seems, but it illustrates the difficulty of achieving by correspondence what is easily accomplished in a face-to-face exchange. The booklet put out by the American Public Health Association was prepared in this Laboratory and is a detailed description of the methods which we have employed. We do not make use, frequently of the polarographic method for lead (although we use it for other analyses), but the dithizone method now being used here is described on page 36 of the booklet. It would be our considered advice to your people to make use of the dithizone method. It is sensitive and precise, and in trained hands will yield consistently reliable results. The polarographic method would be our third choice for several reasons. The spectrographlc method as described in the booklet is quite good, but the results so obtained vary somewhat more widely than those yielded by the dithizone method and, hence, are somewhat less satisfactory. It seems to us very likely that there will be some questions about procedure after your people have undertaken their first analyses, but we believe that the step-by-step description of the dithizone method will be sufficient for their purposes. Mr. Cholak will be glad to answer any question that arises concerning the analytical procedures, and I shall do likewise if problems present themselves in the sampling of the blood or urine. Very truly yours, RAK:vr Robert A. Kehoe, M.D. 0018797