William Withering opens his 1785 treatise not with a triumphant discovery but with reluctance: he writes only because "the use of the Foxglove is getting abroad" and he fears unguided use will endanger lives. The book is structured as a cumulative clinical record, with over 160 cases arranged chronologically and by source—private practice, hospital cases, and correspondence. Withering insists on including every case, successful or not, a decision he admits may invite censure but which he considers necessary for truth. The result is a work that reads less like a finished argument and more like an evolving laboratory notebook, where dosages shift, failures are noted, and the medicine's effects are observed in real time.

A Reluctant Author and a Cumulative Record

Withering frames his preface as a compelled act: "I am at length compelled to take up the pen." He acknowledges his own inadequacy but argues that imperfect instruction is better than unguarded use. The book's structure reflects this caution. Cases are grouped by origin—his own practice, hospital records, and reports from other practitioners—and each is numbered sequentially. The earliest cases show trial and error; later ones reflect standardized dosing. Withering notes that for the last two years he has not altered his methods, yet he still considers them imperfect. This iterative, self-correcting approach is the book's central method.

The Case as Evidence: Successes and Failures Side by Side

The cases themselves are terse, often just a few lines. For example, Case CLV reports that Mrs. B—— took three grains of powdered digitalis nightly for a fortnight "but without any effect." No apology, no elaboration. In contrast, Case CLVIII describes Henry Warren, who was so asthmatic he could neither sit nor lie down, and who after thirty-six hours of digitalis infusion produced urine "in very great quantity" and was discharged cured. Withering does not editorialize; he lets the outcomes speak. This juxtaposition of null results and dramatic recoveries gives the record its evidentiary weight.

Dosage, Duration, and the Body's Response

Withering pays close attention to dosage forms and timing. He uses powdered leaf, infusion, and sometimes tincture, and he notes the duration of treatment precisely: "three spoonfuls of infusum Digitalis every night" for one patient; "a dram and half to half a pint, an ounce to be taken every fourth hour" for another. He also records when the medicine was stopped—often as soon as diuresis began. The body's response, not a fixed course, determines the regimen. This pharmacological empiricism, grounded in observable effects rather than theory, is the book's quiet innovation.

The Hospital as a Site of Systematic Observation

The hospital cases, drawn up by apothecaries Hinchley and Bayley, add another layer of structure. They are more detailed than Withering's private cases, often including prior treatments (squill, myrrh, steel) that failed before digitalis succeeded. For instance, Mary Crockett took sal. diureticus and tincture of cantharides for a week without benefit, then digitalis produced copious urine. The hospital setting allows for controlled comparison: the same patient serves as their own control. Withering's inclusion of these records, written by others in their own words, underscores his commitment to collaborative, verifiable evidence.

Movement Between Scales: From Individual Case to General Principle

Withering repeatedly warns against drawing general conclusions from his cases, noting that they represent "the most hopeless and deplorable" patients. Yet the book's structure—accumulating case after case—inevitably invites pattern recognition. He moves from the specific (Mrs. B——'s failed fortnight) to the general (digitalis works in anasarca and ascites) without ever claiming certainty. This tension between particular and universal is the book's intellectual engine. The reader is left to weigh the evidence, much as Withering himself did over ten years of practice.

Withering's Account is best read not as a finished manual but as a work in progress—a physician's notebook made public. Pay attention to the cases that fail: they are as instructive as those that succeed. Notice how dosages shift, how the medicine is stopped when the body responds, and how Withering lets the data accumulate without forcing a conclusion. The book rewards a slow, sequential reading, following the arc of a doctor learning by doing.