Document KJgMrRGEqbzG0ewkwrZDgQ33Q

A p ril 26, 1934 D r. H ow ard H. Beard T errell's Lab oratories M edical A rts Buildin g Fo r t W orth, Texas D ear Doctor Beard: I sen d you h erew ith , u n fortu n ately aft e r an undue but u n avoid ab le d elay , a r e p r in t of th e a r t ic le r e fe r r e d to in y ou r le t t e r of M ar ch 31. In rep ly to y ou r q u estion on an aly t ical m eth od s, I m ay sa y fe at if th e m e t h o d r e f e r r e d t o ( i . e . H 2S p r e c ip it a t io n , e t c . ) i s e m p lo y e d in a l l th e step s requ ired to se p ar ate out lead , sp ecifically , from p ossib le in terferin g elem en ts in b iological m a t e r ia ls, it m ay be expected to yield l o s s e s o f t h e o r d e r o f m agn it u d e o f G. 06 to 0. 10 m g . u e r sa m p le a n a l y se d . T h er efo r e, if th e sam p le is la r g e , an d it s le ad con ten t is su ch th at th is am oun t is in sign ifican t a s an e r r o r , fee m eth od can be em ployed sa t is fac t o r ily . O th erw ise it is in adequ ate, x can se e no r e aso n at p r e se n t fo r th e rise of su ch a m eth od in view of fe e sp e c ific it y an d se n sit iv it y of su itab le m od ification s of the dith izon e m eth od. We aban don ed th e car b asid e m eth od in 1939, an d h ave n ot r e so r t e d tc it sin ce . Th e r e a so n la y in th e v e r y gr e at su p e r io r it y of th e dith izon e an d sp e ct r o gr ap h ic m eth od s in d ealin g w ith fa ir ly sm a ll sa m p le s of b io lo gic a l m a t e r ia ls. It is n e c e ssa r y , h ow ever , to em ploy one of the v er y carefu lly an d cr itically exam in ed v e r sio n s of the d it h iz n e m e t h o d in o r d e r t o o b t ain u n ifo r m ly s a t i s f a c t o r y r e s u l t s . We d o n o t u s o r a d v o c a t e an y o f t h e sh o r t c u t m e t h o d s, e x c e p t in. o c c a si o n a l scr e e n in g t e st s w h ich a r e to be follow ed up by th e m o r e e lab o r at e m eth od . Very tru ly y ou rs, PxAK e f D ictated but not read . Sn c. R o b e r t A . Ke h o e , M. D. ^ 0019340 NS OF 3LO GY INIDAL PATH O LO GY "R a y - R a d i u m Al l er g y Ch e m ist r y T ER R ELL'S LA BO R A T O R IES The North Texas Pasteur Institute T . c . T e r r e l l M . D . , f . a . c . p ., f . c .a . p ., d i r e c t o r M ED ICA L A R T S SU ILD IN O PHONE FORTUNE 4S61 FO RT W ORTH, TEXAS ABILENE AMARILLO CORPUS CHRIST! FORT WORTH MUSKOGEE larch , 3 1 , 1 9 ^ b r , H .A.Keh oe, k fe t t e r in g Lab or at or i'- o f A p n lied Physio log-m. University of Cincinnati, C in c in n a t i, Ohio,, % Le ar O r . Keh oe, " -tu axes vrculd g r e a t ly a p p r e c ia t e a r e p r in t o f your on t h e in g e st io n o f Lead Compounds" 191-0. a r t ic le on "Exp er im en t al - .onder x f you t p u ld be so k in d a s t o giv e me you r id e a ab ou t th e fo llo v - in p : >,, . t ', ff- P 1" 8 f P in o from su p p o se d ly c a se s o f le a d n o iso n in e r ,, c,, u t i ,, i e the ^ P ^ y b a z i d . t h o d a ft e r p ^ t a t ^ S ' 1ST otTeJ M lS.gc /lo Sc c ! " qUe " n Sh0'",d -03Smg lMd 1000c<=^ * . }^%]c arj ~ H.o*-u.>r,0 ^ -It1- m +t h1 ain tain e odxitthii xi.sztoohhnaeet th is mmee,tt1hh m oodd essthhhoooudu~ll d be nou.pick up u se d , which such sm all amounts of is ver- sen sitive' to le a n . .ou la y;roouu ccaarree ttoo ccoommmmeenntt conn +t.mh i*s . i v d l l g r c a t i 7 a p p r e c ia t e i t , ' Ibn y th an ks, noward t. Bear d , Fn .D. Ch emist 001984