PREPARATION OF SAL AMMONIAC, PHOSPHORUS, SOLUTION OF INDIGO.
Diderot and D’Alembert say that the sal ammoniac of the ancients was prepared with the urine of camels; that phosphorus, as then manufactured in England, was made with human urine, as was also saltpetre.—(Encyclopædia, Geneva, 1789, article “Urine.”)
Sal ammoniac derives its name from having been first made in the vicinity of the temple of Jupiter Ammon; it would be of consequence to us to know whether or not the priests of that temple had administered urine in disease before they learned how to extract from it the medicinal salt which has come down to our own times.
Schurig devotes a chapter to the medicinal preparations made from human ordure. In every case the ordure had to be that of a youth from twenty-five to thirty years old. This manner of preparing chemicals from the human excreta, including phosphorus from urine, was carried to such a pitch that some philosophers believed the philosopher’s stone was to be found by mixing the salts obtained from human urine with those obtained from human excrement.—(See “Chylologia,” pp. 739-742.)
The method of obtaining sal ammoniac was not known to Pliny; he knew of gum ammoniac, which he says distilled from a tree, called metopia, growing in the sands near the Temple of Jupiter Ammon, in Ethiopia.—(Nat. Hist. lib. 12, cap. 22.)
“A notion has prevailed that sal ammoniac was made of the sand on which camels had staled, and that a great number going to the temple of Jupiter Ammon gave occasion for the name of ammoniac, corrupted to armoniac. Whether it ever could be made by taking up the sand and preparing it with fire, as they do the dung at present, those who are best acquainted with the nature of these things will be best able to judge. I was informed that it was made of the soot which is caused by burning the dung of cows and other animals. The hotter it is the better it produces; and for that reason the dung of pigeons is the best; that of camels is also much esteemed.” (Here follows a description of the method of distilling this soot.)—(Pocock’s “Travels in Egypt,” in Pinkerton, vol. xv. p. 381.)
“Purifiée, l’Urine sert dans les arts pour dégraisser les laines, dissoudre l’indigo, prépare le sel ammoniac.”—(Personal letter from Prof. Frank Rede Fowke, South Kensington Museum, June 18, 1888.)