Document J3jM1YvZm1Y97XEdLJm11V3j2

P ro f, G. S ie ve kin g $,December 2 X93& Professor Dr* G. Herman Sieveking Rothenbaumchaussee Hr* 211 Hamburg 13 Germany Dear Doctor Sieveklng* It was a pleasure to hear from you some time ago and I have been somewhat tardy in replying by reason of the press of many things de manding my attention* I seem to be in a rush even when I am traveling outside this country* and I am sorry that I have never had the opportunity to talk with you about the many aspects of our mutual problems* I am very much interested in the work which you mentioned on methods of determining the lead content of urine* and I should be very glad to hear of your results* We shall maintain as close contact as we can with Dr* Helntzman in Leuna who 13 also working on lead methods* We shall both check back and forth on cergain samples so as to determine the comparability of our methods* I believe you will find that some modification of the Fischer Laopoldl ,!dithlzonefl method will be found to be most suitable for the analysis of urine* unless one has spectrographlc equipment available. With the dithisone method one may use small samples of urine and obtain quite accurate results* X do not know how much experience you have had with the various methods* but I think it is perhaps worth while to caution you against the use of methods which have not been very carefully checked against small known quantities of lead* I say this only because quite a large number of mis-leading results hove been published from laboratories In this country In which not too critically tested methods have been employed* Moreover the diagnostic interpretation which has been put on many of the results has often been unjustified* I think you will find a fairly adequate discussion of most of our problems in relation to tetraethyl lead and leaded gasolines In the book which I have sent you* I find that the most frequent cause of misunderstanding Is in relation to the handling of gasoline. After fairly large experience and rather critical observa tions, we have come to the conclusion that there are no significant dangers associated with the handling of gasoline containing ccronercial quantities of lead, except with reference to the cleaning of tanks in which the gasoline has been stored for considerable periods of time. I think this problem has been discussed with you and It is probably unnecessary at this time for me to discuss it further* However, if there are any questions in your mind as to the nature and magnitude of this danger* I trust you will let me know so I can give you additional information* Dr. MaeshXe has told me that he talked over with you the question of information which should be made available to the Harbor- authorities In Hamburg as to the exact nature of the dangers associated with the handling of tetraethyl lead. I wonder whether or not you have taken steps to acquaint these men with this problem. It would appear that it might be necessary for them to understand matters rather clearly in order to understand the nature of precautions which we feel it necessary to take in the construction of mixing equip ment. It has occurred to me that you might without inconvenience give me a little assistance In obtaining a copy of an article referred to in the literature which we are attempting to obtain. According to our information an Inaugural Dissertation - Hamburg 1933 entitled "Belfcrag zum Bleigehalt menschlicher Organw was published by Sch* Dsohou* My secretary wrote inquiring and wa3 informed that there 'was no such man. There may be something wrong with our information, but on the other hand it seems likely that you will know of the existence of this article and perhaps you could tell me how we can obtain it. I shall be very grateful for any information you can give me. Very truly yours. RAKjis Hebert' Akehoe,'l4.D.