9 h pl t pr r n l d n l t f tt nd v n d t r n rl f l br r r r h t nr v l th t r n W rd r " r d n f th C n r n Ch tr ld n h r lt h h t nt r t n pp r th Ch Ill n A t 1 t 1 93" . A . Ch . S ., 1 93 Whatever Happened To ... ? l n , 3 5 ( n n b r d O t b r 1 h p p r r tt r d thr h t . A . Ch . S . f r WHATEVER HAPPENED TO HOMBERG'S 1 93 nd 1 9 b t r p rl d nt f d h v n r n t d t th PYROPHORUS? C n r 11 W Cl r t l "Int rn t n l Ch l C n r " . William B. Jensen, University of Cincinnati A . Ch . S ., 1 9 6, 1 h nl nt n f th r l t n b th S t " b r r ph r " d nt ll d v r d b rr d n th pr l n r nn n nt f r th nd Int rn t n l W lh l b r (1 5 -1715 t r nd 1 h l C n r f Appl d Ch tr h ld n r n 1 9 ; An n . tt pt n t extract n " d rl h t l" fr h n A . Ch . S ., 1 9 , 3 7 x r nt f r th p rp f tr n t n r r nt lv r (1 In th r f th xp r nt b r d t ll d th x r nt th d v r t f th r t r l n f James J. Bohning is Professor of Chemistry at Wilkes College, h h h pp n d t b n p t h r p t l Wilkes-Barre, PA 18766 and is particularly interested in the [K (SO Al (SO 3 1 nd n t d th t ft r l n th history of the ACS. He is a Past-Chair of the Division and is pp r t nd br n p n th l t n th dr r d n th currently serving as its historian. r t rt p nt n l b r t nt fl h r lt t n t r ll ht b r tt nt n n f h b d n f n t n l th t f n f h nt p r r th th pr p r t n nd t d f t r - TRANSLATIONS l h h r th r p nt n l nfl bl r ph ph - r nt r b th Ind d d r n h t d nt tr v l n It l h The following experiment is taken from Tiberius Cavallo' s "A h d nv t t d th pr p r t n nd pr p rt f th - ll d Treatise on the Nature and Properties of Air," London, 1781. l n St n f r f ph ph r nt b r lf d nd Readers wishing to submit their interpretations of the chemis- h l t r p rf t d r p f r ph ph r nt v r t f try involved, complete with balanced equations, should send l d hl r d ( n n " b r h ph r " d their answers to the editor by the copy due date listed inside the b h t n xt r f l d l [C (O ] nd l - front cover. Answers will appear in the next issue along with n [( Cl] b r l r d t d th h v n bt n d a fresh puzzle. th r n l r p f r th pr p r t n f l nt l ph ph r fr h nn K n l pp dl n x h n f r t Dr. Higgins' Experiment of Detonating Cupreous Nitre by b r t r nv nt d b Ott G r n h h th h d t f Contact with Tin. h lt ( pr n tr ] t n t th r nd t d b " l ttl n h t f h h b t n t v r t nd b t n t th f n n f b t - lt nd t d t th d r n dr th r b t r t r d nd r v r n n rt r t b tr d t th th n f h ll n n t th r"( App r ntl n th 17th nt r tr n t p f t n t lv n h n l n th nd thr n br dth ld b r th n j t pr Y r r l t t h n th f l t b n t ntl r ll d p t n l d th In r d bl v n h p r t nt nt r t n b th p r ph r lt t l b t n th l h nd r t b h t b nd ph ph r nt b t n b r f l d t f ll p p n h n th t th r nd th h l t b pr d fl t nd n h l - x r nt b rv t n nt l 1711 r n rl 3 l r ft r th r n l xp r nt h n h n r t rn d t All th b n d n p bl th f r t p rt f th th bj t nd f n ll p bl h d p p r d r b n th pr p - ph n n p rt f th lt d l h p rt r t n nd ff r n r t n l f r t pr p rt (3 A n pr n t d th t n h n d n l r nd f th r th pr d t t b xt r f t r-fr lt ( bt n d fr n t n b n t fr th f rth fr th nd f th l 3 th l nd n l nfl bl l ( bt n d fr th A tr n fr th n p n d th d r t r th x r nt h p t l t d th t t p nt n n t n d h n f p n tr f 5 t nt l r bl t t th r t n f th lt th th t r n th r th th f n r Expl n nd f r h h b r t nd f th t n- r t n f l [C O] nd t r th r t n pp - f l n v r l pl f t b v r th n dl n r t d ff nt h t t n t th nfl bl l b r n t ll d r b d h xt r t n th r nd h An r t t I zzl f "ph ph r " b t l t r d pt d th r ppr pr t t r f "p r ph r " - rd h h v nt ll t n f ll r d r r p n r r v d nd nd d t t th p nt n l nfl bl l d h r pr p rt f ll t Ch 3 (19 9
pyrophorus by heating together a mixture of charcoal and potassium sulfate. He further showed that both moisture and fire air were essential for ignition. His explanation of the ignition process was based on his personal version of the phlogiston theory in which the charcoal saturated the liver of sulfur with phlogiston. In the presence of moist air, the attraction for water of the alkali in the liver of sulfur forced out this excess phlogiston, which was then seized by the oxygen of the air to produce heat in accord with Scheele's hypothesis that:
phlogiston + fire air --> heat
and the resulting increase in temperature kindled the remaining charcoal. The same year Lavoisier (1743-1794) did a quantitative study of both the formation and ignition of the pyrophorus (8). S h l n t d th n t f t r nd x n In the first of these processes he showed that, in addition to f r th n t n pr elemental sulfur and liver of sulfur in the pyrophorus itself, a mixture of fixed air [CO ] and heavy inflammable air [CO] was also produced, and he further showed that the pyrophorus the material intrigued Homberg's contemporaries and the could be synthesized by directly heating a mixture of charcoal, attempts to unravel its chemistry would eventually command sulfur and fixed alkali (potassium or sodium carbonate). Dur- the talents of some of the 18th century's most celebrated ing ignition, Lavoisier found that the pyrophorus gained weight chemists (4). while simultaneously absorbing oxygen from the air - a process The first advance was made by Homberg's associate, Louis corresponding to the reoxidation of the sulfur and liver of Lemery (1677-1743), who demonstrated in 1714 that the sulfur to sulfuric acid and its eventual combination with the excrement could be replaced by a variety of other combustible fixed alkali to produce an alkali sulfate. animal and plant substances, including wood, blood, flesh and Though Lavoisier's rationale is essentially the one Spanish fly (5). He further postulated that the function of the accepted today, his contemporaries continued to debate both combustible was to reduce the vitriolic acid in the alum to sulfur and that the resulting intimate mixture of sulfur and the unused organic combustible accounted for the mixture's inflammability. An even more significant observation was made by Le Jay de Suvigny in 1760, when he discovered that alum was also not an essential ingredient, but rather an indirect source of alkali sulfate, and that, consequently, suitable pyrophors could be made by directly using pure potassium or sodium sulfate (6). He further postulated that the product contained a mixture of sulfur and sulfuric acid and that the heat generated by the latter on reacting with the moisture of the air was sufficient to inflame the sulfur and so account for the ignition. In 1777 the Swedish apothecary and chemist, Carl Wil- helm Scheele (1742-1786), devoted a section in his famous book on A r nd r , in which he first described his discovery of fire air or oxygen, to the now infamous pyrophorus (7). After first observing that "the kindling of this strange chemical product has already caused vain efforts to many in the endeavor to explain it clearly", Scheele suggested that the net result of heating the alum and combustible was to produce an intimate mixture of charcoal and liver of sulfur [K2S]. He then pro- v r f r t r n z d th x t n f nd x d f ceeded to test this hypothesis by successfully synthesizing a rb n r lt f h nt t t v t d f th p r ph r ll t Ch 3 (19 9 3 th n t r f th p r ph r nd th h n f t n t n bl h h r d n f th I n t n t n ll nt th f r t d d f th 19th nt r h r t (175 -1 h ll n d S v n n t n h p th t n A / l AS/ l K -1 AG/ l t 93 K n 177 nd S h l nd th G r n h t h nn Göttl n (1755-1 9 rr d t p l n 17 n th n t f - - 1 - f x d l l n t pr p r t n In 17 l tr d z r (175 - 5 -9 5 -9 17 5 n t d th t h l nt l ph ph r h d t b -191 7 7 77 - pr nt n rd r t nt f r th p nt n nfl - bl l t h r n 17 th En l h n n p t l t d b n t n th n tr -l d n th r nd ft r v l t n f th l l t l rt d t n nv lv n C + C ( ( (5 th pr n f t ll p t nd d b n t pp r (9 - nd th nt r pr n t t d b th t r ttr t d b h f n l n n r h d b th 1 3 l ttl r th nh dr lf d h th p p l r l d t t r t n th n n r l b r t n f v r r n l r (1 In b t n z n t l nd l d d n r n n tr t d rn t r t nv lv th r d t n f th l l lf t nl d l t r d n tr t n r n t t d b th rb n v t l t thr p t n r t th th f n l dd n dr p f t r t th t r t n r th n t d p r d l l lf d fr r t n 1 nd nd th n- x th r th b t n f rb n n r t n 5 nd r t d rb n pr f rr bl pr p r d b lt n p r l - l r x th r th n th b t n f th n f n r n p nd b n th t p rt nt t v pr d t h v r bl nt f fr lf r pr d d h h C ( + -- CO ( + 1-1 ( ( l n t d b v r pr b bl n r t d b th th rd r t n Int r t n l r t n r l t d t t n 1-3 h v l b n t d d p bl t n th n t n f bl p d r (11 nd n th f d lt p bl t n th ( K (SO ( + C — K S + C ( bl n pr f r th n f t r f d rb n t (1 h h b r p r ph r nt n d t b nt n d K (SO 3 + C ( K S( + CO ( n f th r pr h n v t xtb n th f r t h lf f th 19th nt r t n t t h ll n d b th K2(S04 ( + 2C ( — K2(CO ( S ( + CO( d v r f v r t f th r p r ph r n th 1 3 nd 1 In 1 31 th A r n h t b rt r (17 1- 1 5 r p rt d th d v r f p r ph r d v th A nd t d b th th r d n d t n bl 1 ll f th th r l d p t n f r n bl (13 nd n th p r d pr b th r d n ll f bl t h h t - b t n 1 37 nd 1 th G r n h t d lph M r p r t r nd nd d pr b bl pr d ll b l th t - (1 -1 1 h d h t l r n b r f p r - p r t r d t th p f th pr d t nt th ph r v p r l f l d rb x l t lt (1 h r rr nd n t ph r h pl r t pr p r th n b r p r ph r nd r I n t n d t th h hl x th r ( bl x d t n t ll d l t r d n tr t n f th f n l d p r d l l lf d h h l b f th n p r ph r l rl d ff r nt fr th t f b r pr p r t n nd l n t d K S( + — K (SO ( th h p f n h l r t n l An nd r t nd n f th th r d n v r th n t p t f th h h n t rn n t th rb n t r l n t r ll n fr th l t r t r f th p r d th h th r l f rf r nd nt t x n ppr t d nd xpl tl d d b M rr rl bl 1 h h r d n f th r p r t n t n 1 7 (1
A / l AS/ l K-1 TIC at AG = 0 t n f r n nd t
1 137 1 3 5 1 1 r b r ph l d t n b r rt n t n A 1 1 t r f Ch tr , l 3 M ll n nd n 19 pp - 3 31 9 h n h t r f Ch tr , C lb rn nd ntl nd n 1 3 p ll t Ch 3 (19 9
3 W b r M . A d. l. S 1711 , 3 nd Ib d., 1711 4 , 3 7 Ext n v En l h xtr t n b f nd n th En l h tr n l t n f rr M r El nt f th h r nd r t f Ch tr h h r pr nt d n p rt th rt l n h tr n th f r t d t n f th En l p d r t nn , l ll nd M f r h r Ed nb r h 1771 pp 175-177 S r z d n K pp G h ht d r Ch , d r n h 1 7 pp - 7 5 S r f r n S v n A d. l S . M .d v. S ., 1760, 3 1 7 C W S h l Ch h Abh ndl n nd r ft nd d r, S d r Upp l 1777 En l h tr n l t n b bb n n h C ll t d W r f C rl W lh l S h l , ll nd n 1931 pp 1 -15 A v r "Exp r n r l b n t n d l l v l t r h rb nn t r l lt r t n " M . A d. l. S ., 1777 3 3 pr nt d n O vr d v r, II I pr r I p r l 1 pp 199- hn W M ll t (1 3 - 191 9 r th S h l d b t bb n (7 pp 3 -3 nd f r th th r K pp ( research program. As research chemists, we had developed 1 S M rr A S t f Ch tr , l 3 n n some expertise in the study of materials (either of the material r t nd Or nd n 1 7 pp 5 3-5 nd Gr h itself or the analytical techniques that could be used to charac- El nt f Ch tr , nd l n h rd h l d lph A 1 3 terize the material). Whether through our own readings and p 3 interest in history or through the contact with archeologists, we 11 b r n . . S . ( nd n , 1 , 557 559 have become aware of the fact that our chemical expertise can 5 7 57 be used to study those artifacts which are the reminders of 1 M t r "On th rt l d b C rb n n d n th mankind's past. As new techniques are developed and applied S lf t f th Al l " . Ch . S ., 1 7 , 75 to the study of archeological materials, we continue to learn 13 r " r ph r " A . . S . Art., 1831, , 173 more about the way early man utilized a wide range of h b tr t r f r Ch h C ntr l l tt (1832, , 3 l d resources. th t th pr p r t n h d b n n n l n b f r r r p rt While the application of chemical techniques to the study 1 W r "Ob r r t ll n n hr r r r ph r " . of archeology continues to bring about new knowledge, the r . Ch ., 1837, 8, 77 (Ch . C nt., 1837, 8, 51 nd "Ob r d idea of studying the past using chemical methods is almost as rh lt n hr r r n h S t ff z l h p r x d n d r tz old as the formal study of chemistry itself. I was most surprised nd n n r ph r " Ann. h r ., 1 4, 7 (Ch . C nt., to learn this fact when I heard John Sharkey's address on John 1 11, 7 r dd t n l x pl Ch . C nt., 1 , W. Mallet, the seventh president of the ACS (presented to the 3 b d., 1 , 77 nd b d., 1845, 6, 3 HIST Division at the 1987 National ACS Meeting in New Orleans). While I attended this lecture to learn more about this famous early chemist's long-time association with the Univer- William B. Jensen holds the Oesper Position in Chemical sity of Virginia, I also learned that his Ph.D. dissertation was Education and History of Chemistry at the University of based upon his work as an "archeological chemist". Mallet Cincinnati, Cincinnati, OH 45221. (1832-1912), a charter member of the ACS, made many contributions to chemistry including the determination of the atomic weights of Al, Li, and Au. However, I will ignore many BONES AND STONES of the other fascinating aspects of Mallet's research and focus on his early studies of gold artifacts. What Do Chemists Learn from the Past? During the summers of 1851 and 1852, young John Mallet traveled from his home in Dublin, Ireland (where he had Ralph Allen, University of Virginia already begun his study of chemistry at Trinity College) to Göttingen, Germany. He worked in the laboratory of the Chemists who are involved in the investigation of archeologi- famous chemist Frederick Wöhler (1800-1882) who was himself cal materials are often asked, "Why study the past?" For most a pupil of Berzelius. He brought with him a wide variety of of us, archeological chemistry was not originally a part of our Celtic antiquities from the Museum of the Royal Irish Acad-