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A cheese-like pattern of necrosis, often associated with tuberculous granulomas but not uniquely diagnostic of tuberculosis. Architecture, microbiology and the surrounding viable tissue help establish the cause.

The typical contrast is between a highly cellular, relatively scantily supported encephaloid cancer and a fibroplastic growth composed predominantly of elongated cells and developing fibrous material. Neither historical name is a complete modern tumour classification.

In encephaloid cancer, a thin preparation from a viable region shows crowded, variably sized cells, often rounded, oval, polygonal or irregular, with conspicuous cell nuclei and a prominent cell nucleolus. Some cells have more than one cell nucleus; the cytoplasm and nuclear proportions vary. In sections, the cells form masses or groups separated by a comparatively delicate vascular stroma. Where the lesion is a carcinoma, cohesive epithelial arrangements and invasion of surrounding tissue help establish its nature. The scant support helps explain the soft, brain-like gross consistency denoted by “encephaloid”; it does not mean that the growth is made of brain tissue.

A rapidly growing soft tumour may also show evidence of mitosis, haemorrhage, necrosis and granular or fatty cellular debris. These features vary with sampling and are not the definition of every historical encephaloid lesion. The viable advancing edge is more informative about cell type and invasion than a completely broken-down centre. A modern interpretation combines architecture, cell morphology and, where needed, immunohistochemistry; one large nucleolated cell is not a universal “cancer corpuscle.”^[ref][ref]

In a typical fibroplastic growth, the conspicuous elements are oval or spindle-shaped cells, with elongated cell nuclei, tapering processes and intercellular material taking on a fibrillar character. The cells may run in parallel bundles or interlacing groups. Some areas contain many apparently free oval cell nuclei; other areas show more mature fibres and fewer obvious cell bodies. A teased preparation helps display individual elongated cells and fibres, whereas a section shows how the bundles relate to vessels and surrounding tissue.

The historical interpretation was of a growth resembling developing connective tissue. It should not be translated automatically into either a harmless fibroma or a specific modern fibrosarcoma. Contemporary descriptions recorded recurrence and malignant behaviour in some growths put in this broad category.^[ref] Cell shape must be read with tissue architecture and behaviour. Apparent resemblance to fibroblasts does not establish benignity, and a scant-fibred soft growth is not by itself proof of epithelial origin.

Typhus and typhoid fever are distinct infections, despite their overlapping fever, prostration and delirium. In the British historical comparison, typhus chiefly means epidemic louse-borne typhus, not every disease now called a typhus fever.

Classical typhus often begins relatively abruptly with severe headache, fever, prostration and a conspicuously ill mental state. Its eruption is commonly a more extensive dusky maculopapular rash on the anatomical trunk and limbs and may become petechial. Crowded conditions and infestation with body lice support the epidemiological distinction. Modern knowledge identifies Rickettsia prowazekii and transmission involving infected louse material. Injury to small-vessel endothelium helps explain the widespread illness; it is not chiefly a local ulcerating disease of the ileal lymphoid tissue.^[ref]

Typhoid fever more often develops insidiously, with persistent fever, headache and progressive weakness, together with abdominal discomfort, distension and either constipation or diarrhoea. Sparse, transient rose spots may occur on the anatomical trunk. Splenic enlargement and intestinal complications are important. The characteristic pathological process involves intestinal lymphoid tissue, especially Peyer's patches in the terminal ileum, with enlargement, necrosis and ulceration. Severe ulcers can bleed or perforate.^[ref]

Modern causation separates typhoid fever, due to Salmonella Typhi, from louse-borne typhus. Typhoid fever spreads through food or water contaminated by human excreta, including material from carriers; it is not acquired merely because an air space is crowded. A prolonged course, abdominal findings and intestinal haemorrhage favour it, whereas abrupt severe illness with a widespread dusky rash and louse exposure favour typhus.^[ref]

Neither the rash nor the bowel habit is invariable, and the old contrast between an approximately two-week typhus and a longer enteric illness is a tendency, not a diagnostic clock. An absent rose spot does not exclude typhoid fever, and an absent rash does not exclude typhus. Modern confirmation uses organism-appropriate investigations, including blood culture for enteric fever and appropriate serological or molecular testing for typhus. The important historical achievement is the separation of the syndromes; the later microbiological explanation should not be projected into every 1864 diagnostic account.

“Softening” describes disintegration of nervous tissue; it does not identify one cause. The 1865 colour categories were chiefly red, yellow and white softening. They must be distinguished from the causal classification into vascular injury, inflammation, pressure-related injury, trauma and post-mortem change. Historical observers sometimes interpreted pale ventricular softening as a consequence of oedema; modern pathology requires evidence of tissue death before calling such a region encephalomalacia.^[ref]

Red softening contains conspicuous extravasated blood, sometimes with vascular engorgement. It may occur in a haemorrhagic cerebral infarction, a contusion or destructive inflammation. Yellow softening is a later discoloured, friable focus containing products of tissue and blood breakdown, often with lipid-laden macrophages. White or pale softening has little visible haemorrhage; an ischaemic focus in the white matter can be pale, as can waterlogged tissue around a cerebral ventricle. These appearances overlap through time. Neither red colour proves primary encephalitis nor white colour proves absence of vascular disease.

In the cerebral hemispheres, a major cause of genuine destructive softening is interruption of arterial blood flow: thrombosis on diseased arteries, an embolus from the heart or another artery, or inadequate perfusion during severe systemic circulatory failure. The territory supplied by the obstructed vessel helps explain a focal lesion; prolonged global failure particularly injures vulnerable neurons and boundary zones between arterial territories. Cortical lesions and deep lesions involving the basal ganglia or internal pathways can therefore have different distributions. Cerebral infarction evolves through neuronal injury, removal of dead tissue by microglia and macrophages, and liquefactive necrosis; a chronic lesion may leave a fluid-filled cavity with surrounding gliosis.^[ref]

In the cerebellum and brainstem, interruption of the vertebrobasilar circulation is likewise an important vascular cause; local haemorrhage, trauma and infection are alternatives. Suppuration can cause destructive softening in any region, and a nearby tumour can injure tissue by compression, interference with its blood supply or associated oedema. These mechanisms must be investigated rather than inferred from consistency alone.

In the spinal cord, destructive myelomalacia can follow vascular interruption, severe compression, direct trauma or inflammatory myelitis. Vertebral disease or an epidural mass may compress both the spinal cord and its vessels. Infarction often involves the territory of the anterior spinal artery; reduced perfusion can preferentially damage the vulnerable central gray matter. Myelitis can also disrupt tissue without a primary arterial obstruction. It would be misleading to transfer the relative frequency of cerebral embolism unchanged to every spinal lesion.^[ref]

At examination, record the location, vascular territory, firmness, colour and adjacent membranes; inspect the arteries and search for an embolic source or compression. Microscopy asks whether there is necrosis, inflammatory exudation, haemorrhage, myelin debris, cellular clearance or repair. Finally exclude simple post-mortem autolysis.

Angina pectoris is most usefully explained by transient inadequacy of the myocardial oxygen supply relative to demand. It is a clinical syndrome, rather than the name of one visible anatomical lesion. The characteristic constricting chest discomfort may radiate to the arm, neck or jaw and be provoked by effort; the question concerns its causes, not a claim that every chest pain is angina pectoris.^[ref]

The common structural basis is coronary atherosclerosis. Narrowing limits the increase of coronary blood flow that should accompany exercise. An affected heart may receive sufficient oxygen at rest and insufficient oxygen when its rate, force of contraction and wall stress rise. Plaque disruption with thrombosis can abruptly worsen supply; persistent severe ischemia can then cause myocardial infarction. Pain from transient ischemia does not by itself prove myocardial necrosis.

Other mechanisms include coronary artery spasm, impaired regulation of small coronary vessels, or increased demand in left ventricular hypertrophy, severe aortic stenosis, or tachycardia. Reduced delivery through severe anaemia, low arterial oxygen or low perfusion pressure may provoke symptoms even without a new obstructing plaque. Structural narrowing, vasomotor change, blood oxygen-carrying capacity and cardiac work therefore have to be considered together.^[ref]

For an 1865 interpretation, coronary “ossification” or degeneration, diseased cardiac or aortic structures and neural or spasmodic explanations belonged to the historical discussion. These did not establish a single universal cause. A report published in January 1865 described a pathological case associated angina pectoris with diseased coronary arteries, but isolated cases cannot demonstrate that a particular valve or vessel lesion is necessary in every patient.^[ref] The modern supply-and-demand account explains why severe symptoms can coexist with relatively inconspicuous large coronary arteries, and why substantial coronary disease need not cause pain at every moment.

A pathological investigation inspects the coronary origins and course, their lumen and wall, the myocardium, the aortic valve and ventricular thickness. Clinical investigation adds evidence of reversible myocardial ischaemia and distinguishes it from infarction or non-cardiac pain. Modern electrocardiography and appropriate imaging address functions that a nineteenth-century post-mortem inspection alone could not measure. A normal-looking vessel on gross inspection cannot exclude coronary microvascular disease or a transient coronary artery spasm.

Suspected strangulation means threatened or impaired blood supply to herniated tissue; it is more serious than irreducibility alone and can occur without complete intestinal obstruction. The diagnostic assessment must combine the local swelling, abdominal symptoms, general condition and time course.

Ask about a previous hernia, whether it was reducible, a new painful swelling, abrupt failure of reduction, the onset of pain and vomiting, bowel function and prior attempts at manipulation. Examine the relevant sites, including both groins and the femoral regions, rather than attributing unexplained vomiting and abdominal pain solely to a gastric illness. A previously familiar painless lump can become dangerous after years of intermittent reduction. A small femoral hernia may be less conspicuous than its systemic consequences suggest.

Locally, new tenderness, tension, irreducibility and loss of a usual cough impulse raise concern. Erythematous or discoloured overlying skin is more alarming, but can be absent early. Abdominal distension, persistent vomiting and failure to pass stool or flatus support intestinal obstruction. Increasing pain, tachycardia, fever, dehydration, peritonitis or shock suggest advancing compromise. Do not wait for every late sign: prolonged delay can lead to intestinal ischaemia, necrosis and sepsis.^[ref]

Several negative observations are unsafe reassurances. Passage of stool may merely empty bowel below the obstruction. If only part of the bowel wall is trapped, as in a Richter hernia, complete obstruction may never occur. A very ill person may describe less pain late in the course. Disappearance of the external swelling after a forceful manipulation does not prove safe restoration of viable bowel: persistence of pain or obstruction demands reassessment, including possible reduction en masse.^[ref]

An 1866 surgeon relied heavily on these bedside features and on the distinction from an inflamed lymph node, hydrocele, another groin mass or non-strangulated hernia. Contemporary reports describe sequences of attempted reduction, baths, enemata and chloroform before operation. They document period practice; they must not be transferred into a rule that strangulation begins only when repeated reduction has failed.^[ref]

Modern correction: suspected strangulation needs immediate surgical assessment and timely operative treatment. Selected blood tests and imaging, commonly contrast-enhanced computed tomography when useful and feasible, support assessment but should not delay action in a convincing emergency. Normal early laboratory results do not exclude local ischaemia. Current guidance distinguishes an acutely irreducible hernia without evidence of bowel compromise, where supervised reduction may be considered, from suspected strangulation, where emergency surgery is indicated. Ongoing symptoms after apparent reduction also require observation and reassessment.^[ref] The diagnostic goal is not merely to name the lump, but to recognize endangered tissue before irreversible injury.

The classical contrast is between ulceration centred on intestinal lymphoid tissue in enteric fever and granulomatous, often circumferential ulceration in intestinal tuberculosis. The historical expression continued fever covered more than one illness. The characteristic bowel lesions meant here point especially to typhoid fever; they should not be attributed indiscriminately to typhus or every prolonged fever.

In typhoid fever, Peyer's patches and solitary lymphoid follicles, particularly in the terminal ileum, enlarge and become infiltrated. Their breakdown and necrosis lead to sloughing and ulceration. The larger ulcers characteristically follow the long axis of the intestine, reflecting the shape of the affected aggregated lymphoid patch on the side opposite the mesentery. Depending on their stage, one may see swollen patches, necrotic sloughs, open ulcers or healing surfaces. Depth varies; erosion into a blood vessel can cause haemorrhage, while full-thickness destruction can cause intestinal perforation and peritonitis.

Microscopically, the important cellular component includes swollen macrophages with ingested organisms and cellular debris; this is not simply a dense collection of neutrophils forming an ordinary abscess. The surrounding mucosal architecture may become severely disturbed. These current cellular descriptions refine the gross lesion recognized before the causative organism was identified.^[ref][ref]

In historical phthisis, bowel disease frequently meant intestinal tuberculosis associated with pulmonary tuberculosis. Lesions commonly involve the terminal ileum and ileocaecal region, although other sites occur. Nodules in mucosal or submucosal lymphoid tissue undergo caseous necrosis, coalesce and break through the mucosa. The ulcerated surface tends to spread transversely and may encircle the bowel. The edges can be irregular and undermined, with additional tuberculous granulomas in the wall, serosal surface or draining lymph nodes. Progressive fibrosis may narrow the lumen and produce a stricture; thickened masses as well as ulcers can occur.^[ref]

A section from a tuberculous ulcer may show central caseous necrosis bordered by epithelioid macrophages, giant cells and lymphocytes. A section from an enteric-fever ulcer instead emphasizes destruction of lymphoid patches with macrophage-rich infiltration. A practical anatomical examination records site, orientation, depth, edges, intervening mucosa, serosal nodules and draining lymph nodes, rather than judging one detached fragment in isolation.

Longitudinal lymphoid-patch ulcers favour the classical enteric-fever pattern; transverse, caseating and often stenosing lesions favour intestinal tuberculosis. These are useful patterns rather than absolute rules. Modern microbiological culture, organism-specific molecular tests and appropriately sampled histology can establish the cause when gross appearances overlap.