Past exam of the medicine course of the University of Oxford / 1865 / Second examination / Forensic medicine and hygiene (No. IV.)

Original volume: Examination papers for the Degree of Bachelor of Medicine by the University of Oxford (1864–1867). Open the original paper in the scanned volume.

Original questions are transcribed from the public-domain edition. Credit: Wellcome Collection; original supplied by Royal College of Physicians, London. Source and public-domain rights statement.

State the symptoms of poisoning by Sulphuric Acid, Phosphorus, and Strychnia.

Sulfuric acid produces corrosive injury, white phosphorus can cause early gastrointestinal illness followed by delayed systemic poisoning, and strychnine produces painful, stimulus-sensitive muscle spasms. The three patterns should be distinguished rather than treated as one syndrome. “Sulphuric acid” and “strychnia” are the historical spellings used in the examination.

With swallowed sulfuric acid, the principal symptoms are immediate burning pain in the mouth, throat and upper abdomen; excessive salivation; painful or difficult swallowing; and repeated vomiting, which may contain blood. Injury to the larynx can cause swelling, altered voice and obstruction of the airway. Severe gastrointestinal damage can lead to hemorrhage, perforation and circulatory shock. The extent of injury depends on concentration, quantity and contact, so no single appearance of the mouth measures the whole injury. Inhalation of acid mist principally causes irritation, coughing, chest tightness and difficulty breathing; severe exposure can damage the lungs. These are effects of a corrosive substance at its contact sites, not the symptoms of a selectively acting convulsant.^[ref]

For phosphorus poisoning, the relevant toxic material is white phosphorus, also called yellow phosphorus. It should not be confused with ordinary dietary phosphate or assumed to have the same properties as red phosphorus. After ingestion there may be burning discomfort, thirst, nausea, vomiting, abdominal pain and diarrhoea. A garlic-like odour or luminescent vomit can be a clue, but their absence does not exclude exposure. Severe cases can collapse early. More deceptively, symptoms may improve for an interval before renewed illness, jaundice, tender enlargement of the liver, abnormal bleeding, kidney injury, confusion and coma. This sequence reflects delayed systemic injury, especially liver failure; apparent recovery from the first gastric symptoms is not proof that poisoning has ended.^[ref]

Exposure of the skin or eyes to burning white phosphorus can cause severe local burns and also systemic toxicity. Long-term industrial exposure with destructive jaw disease is a different presentation from the acute swallowed-poison pattern. Current institutional toxicology distinguishes these routes and time courses; an 1865 symptom description should not be stretched into a claim that all substances containing phosphorus behave alike.^[ref]

With strychnine poisoning, apprehension, restlessness and muscular stiffness are followed by repeated, intensely painful generalized muscle spasms. Slight touch, noise, light or movement can provoke an attack. The limbs become rigid and the trunk may arch backwards in opisthotonus; jaw closure and facial contraction can give trismus and risus sardonicus. The respiratory muscles may be fixed during an attack, causing difficulty breathing and cyanosis. Between attacks there may be substantial relaxation, while consciousness is initially preserved. The person can therefore be lucid and terrified of another attack. Exhaustion, overheating and ultimately respiratory failure can follow.^[ref]

Repeated violent contractions may produce hyperthermia, acidosis and rhabdomyolysis, with dark urine and acute kidney injury. Initial awareness is characteristic, but advanced hypoxia can abolish it. The pattern differs from the immediate destructive pain of sulfuric acid and the often delayed organ injury of white phosphorus. The modern account of inhibitory glycine receptor blockade explains the stimulus-sensitive contractions, but that receptor mechanism is later knowledge, not something to attribute to an 1865 candidate.^[ref][ref]

What are the symptoms of poisoning by Carbonic Acid, under what circumstances does it usually occur, and how would you prevent them ?

“Carbonic acid” in this question means gaseous carbon dioxide, not liquid acid poisoning. Dangerous accumulation causes hypercapnia, impaired consciousness and potentially death; prevention requires controlling its production and providing effective fresh-air replacement. At high concentrations, displacement of oxygen can contribute, but lack of oxygen is not the only mechanism.

Early symptoms can include headache, dizziness, discomfort, restlessness, sweating, rapid or laboured breathing and an increased pulse. Greater exposure can cause confusion, loss of coordination, profound drowsiness, collapse, convulsions, coma and death. In a heavily contaminated space, collapse may occur before a person can recognize the danger or escape. Carbon dioxide is colourless and odourless, so absence of an offensive smell provides no reassurance.^[ref]

The physiological point matters. Increased inspired carbon dioxide impairs elimination of the body's own carbon dioxide and alters the acid–base state of the blood. A hazardous atmosphere can therefore remain dangerous even when enough oxygen is present to sustain a flame. The modern institutional discussion of carbon dioxide fire suppression distinguishes the gas's direct physiological effects from mere dilution of oxygen.^[ref]

The characteristic settings are poorly ventilated spaces in which carbon dioxide is continuously generated or accumulates: brewery or wine-fermentation vessels, cellars, pits, wells, vaults and places containing decomposing organic material. Fermentation and cellular respiration generate the gas; combustion is another source. In a badly ventilated occupied room, human breathing and unflued fires or lamps add to the burden. A dangerous combustion atmosphere may also contain carbon monoxide, which is a separate poison and requires a separate assessment. Carbon dioxide is denser than air, so low or poorly swept spaces deserve attention; currents and mixing mean that one cannot assume a sharp, motionless layer with safe air above it.^[ref]

For prevention, remove or enclose the source where practicable and maintain building ventilation that actually sweeps the occupied and low-lying spaces. Exhaust contaminated air to a safe place and bring replacement air from a clean source. Opening a small window elsewhere in a building does not establish an adequate supply at the worker's position. Fermentation vessels, pits and similar spaces should be arranged for inspection and cleaning without entry where possible.

The nineteenth-century emphasis on fresh air and caution before entering such spaces remains sound. Current practice adds atmosphere testing for carbon dioxide, oxygen deficiency and other relevant gases, together with controlled entry and rescue arrangements. A burning candle is an inadequate safety test: flame behaviour neither measures carbon dioxide nor rules out a different toxic gas. A rescuer who enters an unknown atmosphere without appropriate protection can become a second casualty. Trained rescue with suitable supplied breathing air and retrieval arrangements must be distinguished from simply holding one's breath and climbing in.^[ref]

For ordinary rooms and wards, prevention also means limiting overcrowding, maintaining reliable air inlets and outlets, and removing products of combustion through proper flues. These principles concern continuing air exchange: a large room merely delays contamination if its air is never renewed. They explain why the following ward question asks separately about cubic space and the rate of change of air.

How would you ascertain whether the dead body of a child found in the water had ever breathed ?

Use a documented examination of the whole body and lungs, with a lung flotation test as corroboration rather than an infallible verdict. Previous breathing, live birth and death by drowning are three different propositions. The question asks how to investigate; it does not supply a body on which to report an actual positive or negative result.

First establish the apparent age and development of the child, the condition of the remains and any evidence about birth, recovery from the water or attempted resuscitation. If the child is evidently older, independent evidence of survival after birth may settle much of the issue. In a newly born child, the forensic problem is harder. Record decomposition, injuries and any manipulation before opening the chest. Avoid inflating or unnecessarily compressing the lungs before their original state has been documented.

On opening the chest, observe the position, extent, colour and consistency of the lungs. Unexpanded newborn lungs are generally compact and do not fill the chest as expanded lungs do. Aerated regions may be more expanded, spongy and crepitant. Cut surfaces may show small air bubbles. These observations support a judgement about aeration, but disease, collapse and decomposition complicate their interpretation. Examine both sides and different regions, because a few breaths may expand only part of the lungs.

For the historical lung flotation test, place the removed thoracic organs in water, then examine the lungs separately, their lobes and representative small pieces. Record what floats and what sinks at each stage, using a vessel deep enough for free flotation. The physical principle is reduction of average density by retained gas. Testing only a whole organ can miss a small aerated region. The test belongs to the pre-1865 forensic toolkit: the contemporary encyclopedia discussed lung flotation and explicitly recognized both artificial inflation and putrefaction as alternative explanations for floating.^[ref]

There are two main classes of error. Floating can result from gas introduced by attempted artificial respiration or generated after death, so it does not by itself prove spontaneous breathing. Look for decomposition elsewhere and compare the distribution of gas in the lungs and other organs. A floating piece of liver can support the suspicion of generalized gas formation, but a sinking comparison organ does not guarantee that all pulmonary gas arose during life. Historical claims that squeezing a fragment always distinguishes breathed air from artificially introduced air were too confident; compression is not a decisive separator of the causes of aeration.^[ref]

Sinking does not establish that the child never breathed. A few ineffective breaths, limited expansion, or heavy, fluid-filled or diseased lung tissue can leave the material tested denser than water. A later prospective autopsy study reported four false-negative tests in which lungs sank despite prior life reported by medical staff. That observation demonstrates why a negative result cannot stand alone; the study's overall performance in its own material is not a universal accuracy guarantee for decomposed bodies recovered from water.^[ref]

Use the whole examination and independent evidence to reach a qualified conclusion. Feeding, healing changes or reliable observations of the living child may support survival, but they are different evidence from lung aeration. A child can show signs of life without establishing effective breathing, and an inflated lung does not establish a particular cause of death. Immersion may have occurred before or after death; neither flotation nor the body's location alone proves drowning. Where decomposition or attempted resuscitation prevents a confident distinction, report the limit rather than manufacture certainty.

What amount of cubic space is required for each bed in a hospital ward? How do you ascertain the rate of change in the Air in a ward? and state the ordinary impurities which may exist in vitiated Hospital Air and the methods in use for examining them.

A defensible period design answer for hospital bed space is roughly 1,600 cubic feet, or 45 cubic metres, per bed in a properly ventilated ordinary ward. This is a volume allowance, not a ventilation rate or a universal legal minimum. In the 1863 third edition of Notes on Hospitals by Florence Nightingale, Florence Nightingale gives a twenty-patient ward measuring 80 by 25 by 16 feet, or alternatively 80 by 26 by 15 feet. These examples give 1,600 or 1,560 cubic feet per bed, respectively.^[ref]

For the first arrangement,This is a cited design example, not a measurement of an unseen ward. Floor area, separation between beds, access for nursing, air distribution and the condition of the patients also matter. Simply adding height cannot compensate for crowding patients together or leaving stagnant zones around the beds. A modern hospital would apply its current design and infection-control requirements rather than treat the 1863 figure as sufficient for every clinical purpose.

To determine hospital ward ventilation, first measure the ward's internal volume $V$. Measure the area $A$ of each effective inlet or outlet and the mean normal velocity $\bar{u}$ across it, using an anemometer and several positions rather than one favourable point. The volume flow is $Q=A\bar{u}$, or the sum of the flows through independent openings of the same side of the balance. Do not add both the incoming and outgoing flow and call their sum new air. Reverse flow, leakage, changes of wind and temperature, and recirculation must be considered. Smoke may reveal direction and stagnant regions, but its visible movement alone is not a quantitative flow measurement. Modern institutional instrument guidance also explains why velocity must be sampled across a section; the simple area–velocity relation itself does not depend on a modern electronic instrument.^[ref]

With $Q$ expressed per hour, the mean air changes per hour areThe quantities have different meanings: $V/N$ is space per bed, $Q/N$ is fresh-air supply per bed per hour, and $a$ is the nominal exchange rate. A system may move much recirculated air while supplying relatively little new outdoor air.

A second method is to follow the fall of a tracer gas after its source stops. Under a well-mixed, constant-flow model with constant outdoor concentration $C_o$ and no continuing internal generation,Here time is in hours if $a$ is to be reported per hour. The formula follows by integrating the mass balance. Compare measurements at several positions and state the conditions. Poor mixing, continuing generation by occupants and changing wind invalidate a simple one-exponential interpretation. Current institutional guidance describes this decay method; the modern monitoring protocol is a later comparison, while the elementary balance explains what “rate of change” measures.^[ref]

The ordinary ward impurities to examine are excess carbon dioxide and water vapour from occupants, volatile material including Ammonia, organic and inorganic dust, and potentially infectious aerosols. Carbon monoxide or irritant combustion gases may enter where heating or lighting is defective; drain-associated gases are a contingent additional hazard, not something necessarily present in every ward. Record occupancy, combustion sources, windows, sampling position, temperature and time, and take an outdoor comparison sample.

For carbon dioxide, collect a known volume of air in a calibrated vessel and expose it to a measured amount of standardized barium hydroxide. Absorption produces barium carbonate. Compare the remaining alkali with a reagent blank, excluding carbonate precipitate from an acid titration that would dissolve it. The consumed alkali gives the absorbed carbon dioxide; express that amount per original volume of air. A report from 1864 describes the method in 7–10 litre globes with a gravimetric comparison, establishing a procedure available before the examination.^[ref]

Estimate humidity with wet- and dry-bulb thermometers, or gravimetrically by collecting moisture in a weighed drying absorber from a measured volume of air. For volatile bases, pass a measured sample through dilute acid and determine the uptake, interpreting possible Ammonia alongside interfering bases. Mere change of litmus is a screen, not a selective low-concentration quantitative assay. A modern example uses acid-treated collection medium and ion chromatography, with calibrated sampling and blanks; that later analytical specification must not be credited to 1865.^[ref]

Collect suspended material on a suitable filter or surface and examine it by microscopy; a controlled gravimetric collection gives particle mass per volume. Such measurements do not by themselves identify pathogens or count every inhalable organism. Period assessments also used potassium permanganate decolourization to investigate oxidizable contamination. The 1865 chemical press already warned that other reducing substances could decolourize it, so a supposed “organic matter” result was nonspecific.^[ref]

Finally, report chemical cleanliness, particle loading and ventilation performance separately. They are related aspects of ward conditions, but one cannot derive freedom from infection from a low carbon dioxide result or a weak smell. Modern infection-control guidance similarly emphasizes that microbial air samples depend on collection method, location, timing and an interpretable sampling plan.^[ref]

What are the diseases which are or are supposed to be caused by impure water ?

The strongest period examples are cholera, typhoid fever, dysentery and other diarrhoeal illness associated with contaminated supplies. Other diseases were attributed to water on weaker grounds; the particular contaminant and route of exposure must be specified. A chemical impurity, an infectious agent and an organism that uses water during its life cycle are different kinds of cause.

For an answer situated in 1865, John Snow's work already provided evidence connecting cholera with swallowed material from an affected person's intestinal discharges, including contaminated drinking water. His 1855 second edition compared populations supplied with different waters, as well as investigating local outbreaks. The persuasive feature is an exposure comparison, not simply proximity to a bad smell. Neither a single chemical analysis nor the later course of an epidemic can by itself settle every link in transmission.^[ref]

For typhoid fever, the association with sewage-contaminated wells or supplies should be explained through infectious excreta reaching food or drink. William Budd's 1861 discussion placed the infectious material in the intestinal discharges and opposed spontaneous generation from ordinary decay. That contemporary reasoning gives a much more precise answer than saying that any foul water creates a fever. Modern knowledge identifies a specific bacterium, Salmonella Typhi, rather than an unspecified product of putrefaction.^[ref]

Diarrhoea and dysentery name clinical patterns with several possible causes. Sewage contamination can convey organisms producing them, but not every episode is a waterborne disease. Current authoritative guidance recognizes transmission through unsafe drinking water of cholera, typhoid fever, dysenteric and other diarrhoeal infections, hepatitis A and polio. The last two are present-day additions to the explanation, not an assertion that their viral agents were identified in 1865.^[ref]

Parasites need the same care about route. Guinea-worm disease can follow swallowing infected tiny crustaceans in unsafe drinking water; it is not caused by a generic chemical property of stagnant water. That life-cycle account is modern corroboration. Other water-associated infections can be acquired through contact rather than drinking, and diseases carried by insects breeding near water form another category.^[ref]

An important example of a nineteenth-century attribution is goitre and the developmental disorder then called “cretinism”. An 1861 review linked their distribution to lime-rich drinking water and treated this as a strong causal demonstration. This is evidence of what was supposed, not a conclusion to repeat as established medicine. Endemic goitre is closely associated with iodine deficiency, and severe deficiency during development can have profound neurological consequences; water hardness alone does not identify the relevant cause in a population.^[ref][ref]

Similarly, malaria should not be explained as poisoning from a mouthful of stagnant water. Its ordinary transmission is through infected mosquitoes; aquatic breeding conditions can affect vector populations without making ingestion the route of infection. Modern public-health accounts distinguish such water-related vector exposure from enteric transmission.^[ref]

There are also genuine noninfectious hazards. Lead can enter drinking water from plumbing and cause lead poisoning; other sources can introduce toxic arsenic. These are poisonings by particular substances, not evidence that every mineralized supply is harmful. Current guidance explicitly distinguishes microbial contamination from naturally occurring or infrastructure-derived chemicals.^[ref]

Thus the sound list is accompanied by a causal distinction: diseases transmitted by contaminated water, diseases merely associated with living near water, specific chemical poisonings, and historical claims requiring correction. Clear, pleasant-tasting water may transmit infection, while a conspicuous harmless mineral constituent may have nothing to do with an outbreak. Epidemiological comparison and investigation of the source are essential to deciding which relation is present.

What are the best disinfectants for a sick room? How far are disinfectants of use? and state the principles on which those act which you enumerate.

The best general measures for a sickroom are removal of the infectious source, cleaning and adequate building ventilation, with targeted disinfection of contaminated objects. A chemical that suppresses smell is not thereby a means of making occupied room air safe. Choice of an agent depends on the material, the organism and the conditions of use.

This distinction is available within the historical period. In Notes on Nursing by Florence Nightingale, Florence Nightingale warned against reliance on fumigations and disinfecting fluids in place of removing the offending material and supplying fresh air. Its advice supplies a contemporary limit on indiscriminate chemical use.^[ref]

An 1865 tract also rejected a universally applicable disinfectant and put removal and cleanliness first. Its further chemical and “miasm” claims require separate judgement.^[ref]

Chlorine preparations, including chlorinated lime and chlorinated soda, were important period choices for contaminated material. In present terms their activity comes from reactive chlorine species, including hypochlorous acid, which damage microbial constituents through oxidation and related reactions. Use on suitable cleaned surfaces or receptacles is a different matter from releasing irritating gas about the patient. Abundant organic dirt consumes the active reagent, so effective contact with the object matters more than an impressive smell.^[ref]

Potassium permanganate and related preparations were promoted as oxidizing purifiers. Consumption of oxidizable dirt or odour does not establish destruction of all infectious organisms. The 1865 tract lists the class; its claim of refreshing room air by liberating oxygen is a historical belief, not a substitute for ventilation.^[ref]

Zinc chloride and iron(II) sulfate were used to suppress decomposition and offensive discharges. Neither altered smell nor acidity proves microbial destruction. Charcoal provides a contrast: adsorption can retain odorous substances without reliably disinfecting an object. The tract lists these agents, but listing them does not establish equal effectiveness against infection.^[ref]

Heat disinfection is valuable where the material can tolerate it: washable linen or utensils can receive a controlled hot process after suitable cleaning. The process must reach the whole object; a warm exterior does not show that a bulky interior received the same exposure. This is distinct from heating a room containing a patient. Burning a disposable contaminated object destroys the material altogether, but is not a general prescription for all bedding, equipment or room contents.

The usefulness of chemical disinfection is therefore substantial when applied correctly to a defined source, and limited when used indiscriminately. Remove excreta and soiled linen promptly, clean spills and reusable objects, protect attendants from transferring contamination, and separate flows of clean and contaminated material. Concentration, exposure time, temperature, compatibility and the amount of organic soil affect success. Modern guidance explicitly explains the shielding effect of soil and consumption of germicide by organic contamination.^[ref]

For the room itself, clean accessible surfaces and provide suitable air replacement. Controlled treatment of an empty room or an article is not the same intervention as spreading a pungent vapour in an occupied sickroom. A tolerable smell does not demonstrate efficacy, and an intolerable concentration can injure the patient and staff. Current guidance retains specific roles for disinfectants while emphasizing the separate importance of building ventilation against infectious aerosols.^[ref]

Consequently, disinfect the contaminated material where a suitable process can act; do not use deodorization as a substitute for source removal, cleaning or fresh air. The value and the limits of the agents depend on what they actually do to the source of infection.