Protiodide is an iodide of mercury

Mercury(I) iodide

Mercury iodide is a chemical compound of mercury and iodine. The chemical formula is Hg2I2. It is photosensitive and decomposes easily to mercury and HgI2.-Synthesis:Mercury iodide can be prepared by direct combination of mercury and iodine:...

 and was a very commonly used drug in the 19th century, prescribed for everything from acne

Acne vulgaris

Acne vulgaris is a common human skin disease, characterized by areas of skin with seborrhea , comedones , papules , pustules , Nodules and possibly scarring...

 to kidney disease. It was also the treatment of choice for syphilis

Syphilis

Syphilis is a sexually transmitted infection caused by the spirochete bacterium Treponema pallidum subspecies pallidum. The primary route of transmission is through sexual contact; however, it may also be transmitted from mother to fetus during pregnancy or at birth, resulting in congenital syphilis...

. It was available over the counter at any drugstore, the most common form being a concoction of protiodide, licorice, glycerin and marshmallow

Marshmallow

The marshmallow is a confection that, in its modern form, typically consists of sugar, corn syrup, water, gelatin that has been softened in hot water, dextrose, vanilla flavourings, and sometimes colouring, whipped to a spongy consistency. Some marshmallow recipes call for egg whites...

.

Taken orally, and in low doses, protiodide causes excessive salivation, fetid breath, spongy and bleeding gum

Gingiva

The gingiva , or gums, consists of the mucosal tissue that lies over the mandible and maxilla inside the mouth.-General description:...

s and sore teeth. Excessive use or an overdose causes physical weakness, loss of teeth, hemolysing (destruction of the red blood cell

Red blood cell

Red blood cells are the most common type of blood cell and the vertebrate organism's principal means of delivering oxygen to the body tissues via the blood flow through the circulatory system...

s) of the blood and necrosis

Necrosis

Necrosis is the premature death of cells in living tissue. Necrosis is caused by factors external to the cell or tissue, such as infection, toxins, or trauma. This is in contrast to apoptosis, which is a naturally occurring cause of cellular death...

 of the bones and tissue

Tissue (biology)

Tissue is a cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. These are called tissues because of their identical functioning...

s of the body. Early signs of an overdose or excessive use are muscular tremor

Tremor

A tremor is an involuntary, somewhat rhythmic, muscle contraction and relaxation involving to-and-fro movements of one or more body parts. It is the most common of all involuntary movements and can affect the hands, arms, eyes, face, head, vocal folds, trunk, and legs. Most tremors occur in the...

s, chorea

Chorea (disease)

Choreia is an abnormal involuntary movement disorder, one of a group of neurological disorders called dyskinesias. The term choreia is derived from the Greek word χορεία , see choreia , as the quick movements of the feet or hands are vaguely comparable to dancing or piano playing.The term...

, and locomotor ataxia

Locomotor ataxia

Locomotor ataxia is the inability to precisely control one's own bodily movements. Persons afflicted with this disease may walk in a jerky, nonfluid manner. They will not know where their arms and legs are without looking, but can, for instance, feel and locate a hot object placed against their feet...

. Violent bloody vomiting and voiding

Excretion

Excretion is the process by which waste products of metabolism and other non-useful materials are eliminated from an organism. This is primarily carried out by the lungs, kidneys and skin. This is in contrast with secretion, where the substance may have specific tasks after leaving the cell...

 also occur.

Protiodide has long been banned as a medication

Medication

A pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...

, even though it persisted in use as a quack

Quackery

Quackery is a derogatory term used to describe the promotion of unproven or fraudulent medical practices. Random House Dictionary describes a "quack" as a "fraudulent or ignorant pretender to medical skill" or "a person who pretends, professionally or publicly, to have skill, knowledge, or...

 remedy until the early 20th century. Morgan Robertson

Morgan Robertson

Morgan Andrew Robertson was a well-known American author of short stories and novels, and the self-claimed inventor of the periscope.He is best known for his short novel Futility, first published in 1898...

, known for his 1898 novel Futility

Futility, or the Wreck of the Titan

Futility, or the Wreck of the Titan is an 1898 novella written by Morgan Robertson. The story features the ocean liner Titan, which sinks in the North Atlantic after striking an iceberg...

 which is famous for its similarity to the 1912 sinking of the Titanic, died in 1915 from what is suspected to be a protiodide overdose.