Document N26RgZ9j6M5an3Qo4QBwEYg1p

fi | f fi Johnson RECEIVED DOMESTIC OPERATING COMPANY MA 14 14 R 1977 GEORGLEEE NEW BRUNSWICK N. J. 08903 March 9 1977 Mrs. Lucy B. McCrone Walter C. McCrone Associates 2820 South Michigan Avenue Chicago Illinois 60616 Inc. Dear Lucy Pursuant to our phone conversation today I am enclosing a copy of the comments sent to me by Arnold Schulze FDA microscopist concerning Part II of CTFA Method J4-1 I would greatly appreciate your own confidential comments with regard to 1 The manner in which Part II Asbestiform Amphibole Minerals by Optical Microscopy and Dispersion Staininigs written in terms of its practical application by an optical microscopist of average competence 2 Mr. Schulze's remarks about the method Could his preferred Becke line technique possibly be specific enough for definitive identification of asbestiform amphiboles We had originally employed dispersion staining because it was felt that R.I. measurement ' alone was specific Thank you for your assistance Sincerely we oo oe JPS Enclosure has John P. Schel Ph.D. Central Analytical Analytical Laboratories CC Dr. G. Kaplan F. R. Rolle Mr. G. Lee _ fisnicl JNJTALC000070442