Document zbGw0gyoqYL5bBBX4xb9b6x6n

April 23 19^0 Mr. John Schaefer Ethyl Gasoline Corporation Chrysler Building hew York City TTew York Dear Mr. Schaefer: I wish herewith to confirm my verbal approval of duPcr.t Project # 5526-tl.G. which is concerned with improved facilities for air samplLng in the T.E.L. area. As I indicated in our talk, this project is the result of a discussion with representa tives of duPont in which on the basis of careful studies we demonstrated certain inadequacies in the methods which have been employed up to the present .time in this work, and recommended the use of metering devices which would more accurately indicate the volume of the air samples subjected for analysis. A s you are well aware, the accuracy of methods of air sampling depends upon a high degree of accuracy in the measurement of the sample, as well as a reasonable accuracy in the analytical procedure. In our opinion the analytical procedure is sufficiently accurate but the method of measuring the samples has been grossly in error in some instances and, perhaps, in a large proportion of instances. Accordingly we felt that if any reliance was to be put on air analyses, sufficient effort should be spent in obtaining results which were trustworthy. I am, therefore, glad to approve this pro ject since, indeed, it originated in our recommendation. I return to you herewith the cppy of the Appropriation Request, Very truly yours, RAK:is Robert A. Kehoe, M.D. tfg 0001054