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]
Sulphuric Acid: Toxicological Overview by the UK Health Security Agency. “Health effects of acute or single exposure”, inhalation and ingestion: corrosive burns, dysphagia, vomiting, airway injury and systemic complications
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]
White Phosphorus: Systemic Agent by the National Institute for Occupational Safety and Health. “Signs/Symptoms”, ingestion and delayed effects: gastrointestinal phase, apparent improvement and subsequent multiorgan injury
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]
White Phosphorus by the Agency for Toxic Substances and Disease Registry. ToxFAQs, health effects: ingestion, local burns and chronic occupational jaw disease
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]
Strychnine by the Centers for Disease Control and Prevention. “How it works” and “Signs and symptoms”: painful spasms, arching, initial consciousness and respiratory failure
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]
Strychnine: Biotoxin by the National Institute for Occupational Safety and Health. “Signs/Symptoms”, ingestion: complications of spasms
[ref]Strychnine Poisoning by the California Poison Control System. Discussion, glycine inhibition and clinical comparison
The strongest evidence is a genuine reaction of living tissue, particularly established inflammation or wound healing; bleeding, gaping and a clot are supporting observations, not individually decisive proofs.
Examine the whole body before disturbing the wound, recording its situation, dimensions, margins and relation to damaged blood vessels. Then expose the wound track by careful dissection. An injury received while the blood circulation was active may show substantial hemorrhage, blood infiltrating the surrounding tissue, and adherent blood clots. Infiltration is more informative than loose blood merely lying on the surface: serial cuts can show whether blood has penetrated the tissue rather than simply coated it.
The interval of survival changes what can reasonably be expected. If the person survived long enough, surrounding inflammation, cellular reaction, formation of granulation tissue, or an established scar is evidence of a process that began during life. Such findings can make the conclusion much stronger than the appearance of a fresh cut. They do not furnish a universal clock: wound healing varies with site, severity, health and environment.
A post-mortem cut will often have relatively pale margins and little infiltration, although it can gape because skin and other tissues are elastic. Blood may still escape from a recently dead body, particularly from dependent or congested parts, and coagulation can occur around the time of death. Livor mortis can resemble bruising, while drying and putrefaction alter colour and consistency. A body moved, compressed or subjected to attempts at resuscitation presents further opportunities for artefact. Therefore neither “it bled” nor “the edges retracted” establishes that the wound was inflicted during life.
For modern corroboration, sample the margin, underlying tissue and an uninjured comparison site for histology, interpreting inflammation and other markers in the context of the whole examination. A primary study of decomposed forensic cases illustrates the use of immunohistochemistry while explicitly warning that extravasated red blood cells alone do not reliably establish wound vitality.[ref]
Wound Vitality in Decomposed Bodies: New Frontiers Through Immunohistochemistry. 2021, Introduction and Discussion: ante-mortem injuries, decomposition and limitations of erythrocyte extravasation
Consequently, a rapidly fatal wound may be impossible to distinguish confidently from one inflicted immediately after death by gross aspect alone. Absence of developed inflammation is expected when survival was extremely brief; it is not proof of post-mortem injury. The answer should express the degree of support, rather than force an unwarranted yes-or-no conclusion.