The Chemical Adventures of Sherlock Holmes The Case of the Screaming Stepfather Thomas G. Waddell and Thomas R. Rybolt University of Tennessee at Chattanooga, Chattanooga, TN 37403 The following story provides a problem in qualitative chemical analysis. This is the fourth article presenting a scientific problem in mystery form involving the popular and beloved characters Sherloek Holmes and Dr. Watson (1-3). There is a break in the story where the reader (students and teachers) can ponder and solve the mystery. Sherlock Holmes reveals his solution in the paragraphs following this break. The Stow "Whether I shall turn out to he the hem of my own life, or whether that station will he held bv. anvbodv - -else, these pages must show." A fierce, troubling thunderstorm raged outside the windows of 221B Baker Street. The year was 1897. The time was midnight. Sherlock Holmes, s l u m ~ e in d his chair next to a dim lamp, had just read this passage aloud from a thick, leather volume, spread across his lap. "Holmes," I said, "surely you are not questioning your own d a c e in societv! I dare sav that London would he a far worsk city but for your influence." "Do we ever know, my good fellow? Do we ever really know?" he replied thoughtfully and a bit sadly. "But fear not, Watson," he said, brightening up, "these are not my words, hut those of Mr. Charles Dickens, whom I would strongly recommend on a night like this." "Indeed, Holmes," I said, "yet . . . " A sharp knock on our door interrupted my response. I glanced quickly a t my friend alarmed as I was a t the appearance of a midnight caller. But Holmes rose from the deep chair as if such a visit should he commonplace, tossed his hook next to the lamp, and moved his tall, slender form to the secured entryway. Being nevertheless concerned, I rapidly stationed myself next to the large desk where his scattered crime clippings and black revolver were stored. Holmes unhooked the latch and swung open the door. Before us stood a figure of small stature, drenched by the storm, and surrounded by a puddle of rain water. It apneared to be a vouth of about eiehteen. hatless. with wet strands of hair across his sharp face. "Heln us., Mr. Holmes." he said auietlv. "Mv stenfather is screaming." "Stenfathers often do this. mv hov." Holmes observed. "~ow&er,this inust certainly de anknusual occasion to bring you out so late on a stormy night." "It is, Mr. Holmes! My stepfather, Mr. Timothy Wooley, is ordinarily a very kind man, although I must add, not extremely generous." "I hardlv think that this is a matter for a consultine detective, Mister. . . ?" "Phelps, Mr. Holmes. I am Robin Phelps. My mother married Mr. Wooley last year." Seeing no threat from this clearly shaken lad, I moved away from the security of Holmes' revolver and stood near the &re. "Come sit down, Robin," Holmes said, "and tell Dr. Watson and me why you think we can help you with your angry stepfather."
-
.
.
.
"
a
w
"As I said, sir, he'sscrramingar everyone and everything around him. Something is very wrong, or he perhaps m~ghr be ill." With these last words Robin looked over at me, apparently acknowledging my medical training. W h o lives with you, Rohin, and what are the exact circumstances," Holmes inquired. "We live in a small flat on Charles Street, Mr. Holmes. Me, my mother, and my grandmother on my mother's side. It was a rocky start after my mother's marriage to Mr. Wooley, hut lately we have settled into a peaceful cordiality. Mr. Wooley treats us well, although, as I said before, he is very thrifty, Mr. Holmes, and we live well below our means. Over the last week. he has become increasinelv irritable, until finally tonight he slipped into a terriblerage. "Did vou notice anv nossible svm~tomsof a medical roblem beside this unusual rage?"i interjected. "Well, yes, Doctor. He appears to have acquired a stomach problem since I have noticed him clutching his middle, and once I found him doubled up in a chair in agony!" "Excellent!" cheered Holmes. "Can you tell me about his eating habits?" "Some, Mr. Holmes," Rohin replied. "My mother and mandmother cook for him. Oh, he likes a variety of things: iohblers, fowls of any sort, &memeat, . . . a& quite recently, gooseberries. None of the rest of us like them." I could see that Holmes was alert. "And his screaming and agony have reached a crisis tonight?" "Yes, Mr. Holmes. My mother is distraught and my grandmother is in an angry panic. We can't calm him. We are all frightened of what he might do." "We will help you, Robin. It is indeed wise that you came tonight. Dress for the weather, Watson, and bring your medical hag. There are grim potentialities here." He eave me a side wink and we nrenared to accomnanv ~obin-Phel~ tos his Charles ~ t r e e t ' h o k eand into the'latk nieht torrent. The hansom cab that had hroueht Phelns to ~ a k e Street r was still waiting outside and we soon f k n d ourselves entering the troubled apartment. The Scene of the Crime
As we looked around, we were met with a modest hut comfortable surrounding. Many books were strewn about, obviously much used. There was a n appropriate quantity of family photographs and some sporting equipment hung neatly on the wall. About the kitchen area were the remnants of a cozy evening meal; plates of cooked meat, half empty tea cups, and a dish of brilliantly green gooseherries. In contrast was the tormented family itself. Mrs. Wooley, in her nightgown, was weeping in a corner chair. Robin's grandmother was pacing madly, tearing up tissues and thrashing her arms about in an angry fashion. And in another room, we could hear the screaming stepfather, raving in anger, pain, or both. "See to him, Watson," Holmes said. "Bring him out to the living quarters if you can." The grandmother cringed as he said this, and Holmes slowly walked through the flat, examining each item on the walls, the floor, on tables, and in the kitchen. When I Volume 69 Number 12 December 1992
999
entered the nearby room, Mr. Wooley was lying on the floor of his bedroom bent in obvious agony, his arms wrapped tightly around his abdomen. I was able to guide him awkwardly to the living room and lower him into a soft couch. Holmes had been talking to the three family members and when he saw the condition of Timothy Wooley, he said, in his confident manner, "Stay with Mr. Wooley tonight, Watson. Ease his pain as best you can and comfort the family. I shall return in the morning." With this announcement, Sherlock Holmes strode from t h e a p a r t m e n t carrying a fresh dish of t h e bright gooseberries which the ladies of the house had apparently given him. The evening proceeded in a tense but uneventful fashion. Mr. Wooley's agony subsided a bit and the family gathered around him with what seemed like genuine concern. Soon after dawn, Holmes reappeared, carrying with him the dish he had taken, now lacking the gooseberries, but containing a large steel spoon which I recognized as his own from 221B. He whispered in my ear, "I have much new information, Watson, which should interest you. Particularly, there are a t least five family crises of a similar nature in this neighborhood alone." A Touch of Dejd Vu Meets with Sarcasm
"What!" I cried. Then, embarrassed by my outburst, I took him aside. "Holmes, I was beginning to think that this was another internal family poisoning, similar to the Yellow Prisms case of a few years ago." "Were you, Watson?" he said, with raised eyebrows. "How fascinating that you should conclude that." "What are you going to do, Holmes?" I was hurt by his sarcasm. "Chemistry, my good fellow. This is surely another one of our chemical adventures. I have in fact completed a significant series of analyses already." We gathered our belongings and left the Charles Street flat, walking down the block toward a nearby market section. The rain had ceased and the day was pleasant and cool. Holmes explained his chemical results as we passed neighborhood businesses. "I had my suspicions, Watson, and in conkmation, I took some of the .. eooseberrv " "iuice. diluted it to mask the meen color, and added ammonia solution to it. A deep bluecolor resulted. Mark that. Watson, it is critical. Moreover, acidification with hydrochloric acid caused the blue solution to become nearly colorless again. Treatment then with potas, a distinct red precipisium ferrocyanide, w e ( C N ) @gave tate. I have been workina - all n i ~ hat t my lab bench. ^Anotheranalysis of the gooseberry juice had to be done. The concentrated iuice was treated with sulfuric acid, then grain alcohol. F'rblonged heating released fruity vapors reminiscent of, perhaps, pineapple!" At this point in our walk, Holmes grabbed my arm and pulled me into a small but busy grocery market. We pmceeded to the back of the store and quickly found a large display of jars of Frighteningly green gooseberries for sale to the public. Holmes grabbed the closest jar and forced it open. He inserted his steel sDoon and beean to crush and stir the contents of the jar &th his steel-spoon. To my amazement when the steel s ~ o o was u removedfrom the "iar.. it had been transformed, a; if by the magic of alchemy, to a shiny bronze-like metal. Holmes smiled and turned to me. "Our poisoning is solved, Watson. Our poisoner is identified." 1000
Journal of Chemical Education
Stop Here and Solve the Mystery Although it may require a little investigation, this mystery can be solved using chemical knowledge. Try to answer these questions: 1. What did Holmes' chemical tests reveal? 2. What was the poison used? 3. Who was the poisoner?
The following paragraphs contain how Sherlock Holmes solved the chemical mystery. Compare your answer w his. The Solution Holmes went out of the store and found a constable. I could see them across the street as the Great Detective r a ~ i d l vand curtly informed the attentive officer of his findings. f h a d not a"c1ue to the solution of the mystery. When he came back to the store. we resumed our long - walk back to 221B. Wou will agree, Watson, that although this was decidedly a poisoning case from the very start, there was not a stitch of evidence that the perpetrator was a family member. There were no indications in that direction. I found the family to be stable (despite the panic-stricken grandmother) and the apartment spoke of a secure and reasonably happy living arrangement. The thrifty habits of Mr. Wooley referred to by his stepson rendered no hardship. Thus, I could find no motive for attempted murder. But, more than that, my discovery of five such poisonings in the neighborhood made it much more likely that the poisoner was someone outside the Wooley household. "Mr. Woolev was Doisoned. Watson. to be sure. and I was immediatelydattrac'tedto thk unnat&al green appearance of the eooseberries. which. vou undonbtedlv noticed.. onlv . he ate:When I left charles Street, yon saw me take a quantity of them. The ladies were delighted by my interest, but I was not, fortunately, destined to eat these berries. "An aqueous solution of copper will turn deep blue with ammonia whereupon a complex is formed. I obsewed this with the goosebeny juice. This complex is broken up by treatment with acid. And then when the copper solution encounters the reagent potassium ferrocyanide in a n acidic environment, a red precipitate forms. This precipitate consists of a ratio of two copper, one iron, and six cyanide. I observed this cupric ferrocyanide formation. My own research shows that these steps do c o d i the presen* of a poisonous copper salt." My own chemical knowledge was far inferior to Holmes' yet I was determined to inquire further. "But the pineapple aroma you mentioned, Holmes. What did that tell yon?" Gooseberries Plus Greed Yield Poison
"My heating of the concentrated gooseberryjuice with alcohol and sulfuric acid released the fruity-smelling ester that has to form under these conditions. This confirmed the presence of acetate, the charged anion of acetic acid. The poison was verdigris!" 'Verdigris, Holmes?" I t was clearly a poisoning, but I comprehended neither the chemistry nor the culprit. "Verdigris is from the old French verd de gris or verd de Greee, that is green of Greece," said Holmes. "It is a poisonous compound prepared by treating copper with acetic acid. It forms the acetate of copper." "But who was the perpetrator, Holmes?" "It was the grocery store manager, my good fellow! And greed was the motive. Verdigris addition to gooseberries gives them a stunning green color which gives the fruit a greater appeal. The addition of colored mineral salts to foods is an immoral act and thanks to the Adulteration of
Food and Drink Act passed by our own Parliament in 1869, a criminal act as well (4 1. "But Holmes, how did you transform the metal of your spoon when you stirred the gooseberries?" "A layer of copper metal formed on the spoon and this was the cause of the seeming transformation. The steel spoon established the presence of copper in the store's own gooseberries. The cupric ions plate out, reduced by the iron in the spoon." A Hero Once Again
"Copper, Holmes," I said. "A copper poisoning with severe gastric pains. You have saved many lives today. You
have no reason to doubt that you are a hem in your own life." "Ah," he replied. 'You are referring to that Dickens passage I read to you last night. Well, Providence anticipated all this, my friend. What I read to you were the first lines of the novel, David Copperfield!" Literature Cited 1. Waddell, T. O.;Rybolt,T. R. J. Cham. Edue. lM9.66.981482. 2. Waddell. T G.;Rybolt.T.R. J Chem. Edue 1980.67,10061009 3. Waddell T. G.:Rybolt,TR. J. Cham. Edue. 1981,68,10ZM024 4. Reese, K M . Chem andEng News, November 6,1990,60.
provocative opinion The Problem with P. Chem. Robert J. Moore Haverford College, Haverford, PA 19041 Richard W. Schwenz University of Northern, Colorado, Greeley, CO 80639
The physical chemistry course has long been known partially to "set the tone" of the chemistry major. It is, therefore, incumbent on the physical chemistry instructor to present this material in a manner that excites students, illustrates theusefulness of the material, andgenerates an understanding of the chemistry, rather than as a series of dull mathematical abstractions upon which the foundations of chemistry are laid. We believe that there are several indicators of whether this is being accomplished. Statistics
First, data from the National Center for Education Statistics shows a dramatic decline i n t h e number of bachelor's-degree chemists. During the period 1970-1990, the number went from 12,000 annually to 8,000 annually. Second, according to the National Research Council, in the period 1978-1990, the number of PhD's in chemistry pmduced by U S . doctoral-granting institutions increased by a healthy annual rate of 2.7%. The annual rate of growth in the number of PhD's in the disciplines of analytical chemistry (4.5%) and inorganic chemistry (2.6%) exceeded or matched the rate of growth of chemists as a whole. The growth in organic chemistry PhD's was lower, about 0.4% per year, although lumping pharmaceutical and polymer chemists in with the organic chemists raises the growth rate to about 0.9% per year. The annual rate of growth in the number of physical and theoretical chemistry PhD's in the same ~ e r i o dwas 0.4% annuallv. a rate that is not statistically different from zero. In 1978,23.1% of all PhD deg e e s in chemistry were in physical chemistry. By 1990 that figure had dropped to 18.9%. We believe that these trends are indicators of the interest in the areas of the ~hysicalchemistry courses, rather than of physical h e m istry. Clearly the practitioners of organic and physical chemistry need to encourage students to work in their disciplines.
Trend of Zero Growth in P. Chem Students This trend of zero growth is especially puzzling in light of the tremendous progress made in physical chemistry research over the past 20 years. For example, the advent and continuing development of lasers, combined with molecular beam techniques, have revolutionized molecular spectroscopy and chemical dynamics. The parallel development of computers and computational techniques has created a climate in which experimental and theoretical physical chemists are engaging in fruitful collaborations a t the frontiers of their specialties. Physical chemists are now able to use ultrashort laser pulses to study the chemistry of transition states, and to synthesize intriguing species such as the celebrated soccer-ball shaped Csomolecule, Buckminsterfullerene. However, instead of being attracted to physical chemistry research by all this excitement, students are staying away in droves. Share the Excitement in Modern Physical Chemistry We believe that most chemistry majors are not aware of the level of excitement in modern ~hvsicalchemistrv simply because we, as teachers of ph;s~cal chemistry, do not tell them about it. This is a major crime, because all chemistry majors pass through physical chemistry lecture and laboratory on their way to advanced courses in chemistry. In fact, physical chemistry is often cited as one of the courses setting the "tone" of the chemistry major. A brief examination of the physical chemistry curriculum, as it is taught at most institutions, will serve to illustrate the problems with "P. Chem." Typical p, Chem program Physical chemistry typically is taught as a two-semester survey course in the third year of the chemistry currimT~~~~~ generally include classical .1, kinetic theory of eases. chemical kinetics.. auantum me. chanics and spectroscopy, and sometimes statistical mechanics, in that order. The laboratoryis either linked to the lecture, with experimental topics tied as closely to the lec-
Volume 69 Number 12 December 1992
1001
