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Incoming links: A Manual of Practical Therapeutics by Edward John Waring (1865)
The chief historical examples are rhubarb, senna, santonin and logwood for urine; iron preparations, bismuth preparations and charcoal for darkening the faeces. There are two different processes: a substance absorbed and subsequently excreted can colour a secretion, while material remaining in the intestinal lumen can colour the stools without demonstrating systemic drug absorption.
- Rhubarb colours urine yellow to yellow-brown; the colour becomes redder in an alkaline solution. The contemporary account also reports coloration of sweat and breast milk. This is a historical observation about passage of colouring matter, not a claim that every constituent passes unchanged into every secretion. [ref]The Essentials of Materia Medica and Therapeutics by Alfred Baring Garrod (1865). Labiatae, continued, Rheum: colouring constituent, alkaline solutions, and coloration of urine, perspiration and milk
- Senna can give urine a yellow-brown or red-brown colour. The effect is still recognised in current medicinal information. [ref]Senna by the NHS. Side effects, coloration of urine
- Santonin, used historically as an anthelmintic, can make urine conspicuously yellow. This must be distinguished from the drug's separate effect on colour vision: a yellow-looking visual field is not itself excretion of a yellow pigment. [ref]A Manual of Practical Therapeutics by Edward John Waring (1865). §2416, physiological effects and yellow urine
- Logwood can give urine a pink or reddish colour, particularly when it is an alkaline solution; the historical description notes that addition of Ammonia brings out the colour in a previously acid specimen. [ref]The Essentials of Materia Medica and Therapeutics by Alfred Baring Garrod (1865). Cisalpinae, Haematoxylum, urine coloration
- Iron preparations can darken faeces; bismuth preparations also cause dark or black stools. In these examples the result need not be a pre-existing vegetable dye simply passing unchanged through the body. Current information confirms black stools with oral iron and with the modern bismuth medicine bismuth subsalicylate; the latter is corroboration of the colour effect, not an identification of that modern formulation with the 1864 bismuth articles. [ref]Bleeding from the bottom by the NHS. Dark stools and iron tablets[ref]Pepto-Bismol by the NHS. Side effects: black stools and black tongue
- Charcoal supplies a black material directly to the bowel contents. Its appearance in the stools does not require its absorption and subsequent renal excretion.
Colour alone does not identify either the drug or a disease. A medicinal pigment can resemble blood or a bile pigment; pH, timing after administration and appropriate chemical or microscopic examination distinguish possibilities. Conversely, a history of taking a colouring medicine does not prove that an observed specimen contains no blood. These examples describe pharmacological and historical observations, not results from an unseen specimen.
The 1864 iron list includes metallic, ferrous, ferric and compound preparations; its wet Ferri Peroxidum Hydratum was used historically as an antidote to arsenic poisoning. It must be distinguished from dried Ferri Peroxidum and from later editions' reassignment of similar Latin names.
The officinal articles and preparations are:
- metallic forms: iron wire, Ferrum, and Ferrum Redactum;
- simple salts and oxides: Ferri Arsenias, Ferri Carbonas Saccharata, Ferri Iodidum, Ferri Oxidum Magneticum, Ferri Peroxidum, Ferri Peroxidum Hydratum, Ferri Phosphas, Ferri Sulphas, Ferri Sulphas Exsiccata and Ferri Sulphas Granulata;
- complex salts: Ferri et Ammoniae Citras, Ferri et Quiniae Citras and Ferrum Tartaratum;
- solutions: Liquor Ferri Perchloridi, Liquor Ferri Pernitratis and the preparative Liquor Ferri Persulphatis;
- compounded forms: Mistura Ferri Composita, Pilula Ferri Carbonatis, Pilula Ferri Iodidi, Syrupus Ferri Iodidi, Syrupus Ferri Phosphatis, Tinctura Ferri Perchloridi and Vinum Ferri.
[ref]
The Essentials of Materia Medica and Therapeutics by Alfred Baring Garrod (1865). Iron and successive British iron monographs; Solution of Persulphate of Iron, Appendix A; British compounds distinguished from American additions and older London preparations
[ref]The Prescriber's Analysis of the British Pharmacopoeia by John Birkbeck Nevins (1864). pp. 43–45, iron additions, omissions and names; pp. 55, 63, 67 and 72, compound forms
Prepare the hydrated peroxide by inducing precipitation from the ferric solution with sodium hydroxide, collecting and washing the wet precipitate, and preserving it without drying in a covered vessel. The starting solution is Liquor Ferri Persulphatis, whose “persulphate” here means ferric sulfate, not a modern peroxydisulfate salt. Add the appropriately diluted ferric solution to the alkaline liquor with stirring, allow the precipitate to settle, collect it on a calico filter, and wash with distilled water until the washings no longer give a precipitate with barium chloride. This tests removal of soluble sulfate. The resulting fresh, hydrated material is kept wet; drying gives the separate dried preparation. [ref]
The Essentials of Materia Medica and Therapeutics by Alfred Baring Garrod (1865). Ferri Peroxidum Hydratum; Ferri Peroxidum; Solution of Persulphate of Iron
In modern chemical notation the precipitation can be idealised asThe fresh solid is a hydrated ferric oxide material with variable water content; the equation is not a claim that every pharmaceutical batch is one pure, crystalline iron hydroxide. Its historical use depended on binding dissolved arsenic into less available material in the digestive tract, especially the freshly precipitated, wet state. It was not a universal antidote to every metal or every stage of absorbed arsenic poisoning. Contemporary discussion explicitly identified the new hydrated peroxide as an arsenic antidote. [ref]
The British Pharmacopoeia in Chemical News (1864). 6 February 1864, p. 65, iron preparations and freshly precipitated antidote
[ref]A Manual of Practical Therapeutics by Edward John Waring (1865). §1231, preparation, washings tested with barium chloride, preservation without drying and recent preparation
Modern treatment of significant arsenic poisoning concerns systemic toxicity and may involve specialist-directed chelation therapy; a nineteenth-century ferric paste is not the modern treatment standard. [ref]
Clinician Brief: Arsenic by ATSDR. Patient management, acute exposure and specialist consultation for chelation