Phosphorus (horse)

Phosphorus
Phosphorus. Painting by John Frederick Herring, Sr.
Sire	Lamplighter
Grandsire	Merlin
Dam	Rubens mare
Damsire	Rubens
Sex	Stallion
Foaled	1834
Country	United Kingdom of Great Britain and Ireland
Colour	Bay
Breeder	Robert Wilson, 9th Baron Berners
Owner	Robert Wilson, 9th Baron Berners
Trainer	John Doe
Record	3:2-1-0 (in England)
Major wins
Epsom Derby (1837)

Phosphorus (1834 – after 1843) was a British Thoroughbred racehorse and sire. In his British career he ran three times and won two races. His most significant win came when he overcame a leg injury to win the 1837 Epsom Derby. Phosphorus was later sold and exported to Brunswick, but was unable to reproduce his English form. He was unsuccessful as a stallion.

Phosphorus, a bay horse with three white feet, was bred by his owner, Robert Wilson, 9th Baron Berners, at Didlington near Brandon on the border of Norfolk and Suffolk. Phosphorus' dam, the Rubens mare, an unnamed daughter of Rubens, had already produced one winner of the 1000 Guineas in May-day (1834) and went on to produce another one in Firebrand (1842). She was also the dam of the outstanding racemare Camarine. Phosphorus was a lightly built, unprepossessing horse; viewing him immediately after his win at Epsom, the Farmer's Magazine praised his trainer for the colt's excellent condition, but could find little to compliment in his appearance. The Sporting Magazine was even less flattering, describing Phosphorus as a "weak-looking little cripple".

Phosphorus was unraced as a two-year-old and made his first racecourse appearance at Newmarket in April. Ridden by John Day, he finished second in the Newmarket Stakes, beaten by a length by Rat-trap. Day was also the jockey when Phosphorus returned to Newmarket in May against ten opponents in the Rowley Mile Plate. He started at odds of 5/2 and won easily by two lengths from an unnamed colt by Mulatto. Phosphorus was reported to be "in physic" at the time of this race, meaning that he was running under some kind of medication.