April 17, 1955 Mr.

V ' V* ,, 1 Fe b r u a r y l, 1956 Rot J* J .

tanUNd Snoemsf 10* %$$$ fejr s** Satoam fer %t Stufe iit& ilm;M Q o m im im * , .

November 30, 1955 Mr* V.

ETH YL CORP ORATION 100 PARK AVENUE BUILDING PARK AVENUE AT 41st STREET NEW YO RK 17, N.

vJ.

AIR VAIL Aiigust 26, 1957 Dr.

% Juan 26, 1957 Dr, Keaneth D* Blaokfan Harvard Medical School iCh ild r en 1 H osp ital 500 Longwood Avenue Boston , Mass# Dear Doctor Blaokfan 1 Z an comp lyin g with the fu r t h e r r eq u est in your le t t e r of June 22nd by sending you h erewith a r e p r in t of Cholak** a r t ic le d escr ib in g h is sp ectr ogr ap h la method of lead a n a lys is * We ar e in the process of preparing an a r t ic le fo r p u blication Which w ill d escr ib e the d e t a ils of the "Dlth iaon e8 method o f a n a lys is which we use* As to the methods o f Co lle ct in g sam ples, wa have bad a l l s t a in le s s s t e e l n eed les m anufactured fo r us b y the Max Wocher and Son Company o f Cin cin n a t i, I t is on ly n ecessa r y t o s p e cify {that the n eed le be made e n t ir e ly of s t a in le s s s t e e l, and t h a t th e hub which is commonly u sed in the ord in ary n eedle should be com p letely elim in ated * This r eq u ir es a s p e cia l method of fa b r ica t io n but one which is not d iffic u lt * Obviou sly th ese n eed les ar e somewhat more expen sive than the standard brand* In ob tain in g blood sam ples, we prep are pyrex t e s t tubes in t o which blood and s p in a l flu id can be drawn* These ar e washed c a r e fu lly with clean in g so lu t io n , rin sed r ep eated ly with d is t ille d wa ter , and then r in sed a t le a s t th ree time more with d i s t i lle d w a t e r ,t r ip le d i s t i lle d from e it h e r a pyrex > or a s i l l o a s t i l l , p r e fe r a b ly the la t t e r * These tubes 2 are allowed to d r a in , stoppered with a d e a n cork which has never been used b efo r e, and covered with a clean f i l t e r pape| > which i s h eld In p la ce by a rubber band* The blood sim ple is taken d ir e c t ly from th e vein in t o th e tube by means o f a s p e cia l need and u s u a lly with ou t a syr in ge* (1 o cca sio n a lly take samples in the la b or a tor y making u se o f e p yr ex syr in ge which h as been s t e r ilis e d by b o ilin g in d i s t i lle d water a ft e r which i t I s r in se d three times with t r ip le d is t ille d water, as p r eviou sly mentioned* In gen e r a l, however, X p r efer to le t the blood run d lr e o t ly through the n eed le In to the tube*} When we have sample^ obtain ed b y oth er d o ct or s, we p r ovid e bbth the blood tube and the n eed le* The la t t e r i s clean ed ap p r eviou sly d escr ib ed , put in t o a clea n pyrex tu be, OPZIZM Dr.

Esso Resear c h and Eng ineer ing Co mpany (FORMERLY STANDARD OIL DEVELOPMENT COMPANY) P .

June 29 1951 Mr.

Riker Laboratories, inc Los Angeles, Calif 7 October 1952 P. 0.

ETHYL CORPORATION OP CANADA LIMITED Memorandum of Meeting with Occupational Health Division Department of National Health and Welfare Ottawa, Canada Subject*.

COPY THE CEILDB.Eu 1S HOSPITAL RESEARCH FOOHDAIIQH CLSCIKHATI, OHIO October 24, 1952 Er.

Ke n d a l l Re f i n i n g Co m p a n y P R O D U C E R S , R E F IN E R S A N D M A R K E T E R S 100% PURE BRADFORD GRADE PEN N SYLVAN IA P ET R O LE U M AND ITS PRODUCTS .

UNIVERSITY OF MICHIGAN DEPARTMENT OF NEUROLOGY UNIVERSITY HOSPITAL CARL D.