A theory to explain why picrate salts detonated whereas picric acid itself didn't, was proposed by the French chemists Antoine Fourcroy and Louis Vauquelin in 1806 and reiterated by the French chemist Michel Chevreul in 1809. Picric acid evidently contained enough oxygen within itself — i.e. it was "super-oxygenated" (suroxigéné) (Fourcroy and Vauquelin, 1806), p. 543; (Chevreul, 1809), p. 129) — to combust completely even in the absence of air (because even in the absence of air, heat could transform it completely into gases, leaving no carbon). ((Fourcroy and Vauquelin, 1806), pp. 542–543); (Chevreul, 1809), pp. 127–128) However, when picric acid was burned, the heat that was generated caused some of the acid to evaporate, dissipating so much heat that only burning, not detonation, occurred. In contrast, picrate salts were solids that did not sublimate, thus did not dissipate heat; hence, they did detonate.((Fourcroy and Vauquelin, 1806), p. 542); (Chevreul, 1809), pp. 129–130) See:
A theory to explain why picrate salts detonated whereas picric acid itself didn't, was proposed by the French chemists Antoine Fourcroy and Louis Vauquelin in 1806 and reiterated by the French chemist Michel Chevreul in 1809. Picric acid evidently contained enough oxygen within itself — i.e. it was "super-oxygenated" (suroxigéné) (Fourcroy and Vauquelin, 1806), p. 543; (Chevreul, 1809), p. 129) — to combust completely even in the absence of air (because even in the absence of air, heat could transform it completely into gases, leaving no carbon). ((Fourcroy and Vauquelin, 1806), pp. 542–543); (Chevreul, 1809), pp. 127–128) However, when picric acid was burned, the heat that was generated caused some of the acid to evaporate, dissipating so much heat that only burning, not detonation, occurred. In contrast, picrate salts were solids that did not sublimate, thus did not dissipate heat; hence, they did detonate.((Fourcroy and Vauquelin, 1806), p. 542); (Chevreul, 1809), pp. 129–130) See:
Auguste Laurent (1841) "Sur le phényle et ses dérivés" (On phenol and its derivatives), Annales de Chimie et de Physique, series 3, 3: 195–228; see especially pages 221–228.
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Peter Woulfe (1771) "Experiments to shew the nature of aurum mosaicum,"Philosophical Transactions of the Royal Society of London, 61: 114–130. See pages 127–130: "A method of dying wool and silk, of a yellow colour, with indigo; and also with several other blue and red colouring substances." and "Receipt for making the yellow dye." — where Woulfe treats indigo with nitric acid ("acid of nitre").
V. Bertolasi, P. Gilli, G. Gilli: Hydrogen Bonding and Electron Donor-Acceptor (EDA) Interactions Controlling the Crystal Packing of Picric Acid and Its Adducts with Nitrogen Bases. Their Rationalization in Terms of the pKa Equalization and Electron-Pair Saturation Concepts. In: Cryst. Growth Des. 2011, 11, 2724–2735, doi:10.1021/cg101007a.
Junqueira LC, Bignolas G, Brentani RR (1979). "Picrosirius staining plus polarization microscopy, a specific method for collagen detection in tissue sections". The Histochemical Journal. 11 (4): 447–455. doi:10.1007/BF01002772. PMID91593.
Dumas, J. (1841). "Quatrième mémoire sur les types chimiques" [Fourth memoir on chemical types]. Annales de Chimie et de Physique. 3rd series (in French). 2: 204–232. From p. 228: "C'est sous ce nom que j'ai désigné l'acide carboazotique, ..." (It is by this name [i.e., picric acid] that I designated carboazotic acid, ... )
Welter, Jean-Joseph (1799). "Sur quelques matières particulières, trouvées dans les substances animals, traitées par l'acide nitrique" [On some particular materials, found in animal substances, treated with nitric acid]. Annales de Chimie et de Physique. 1st series (in French). 29: 301–305. From p. 303: "Le lendemain je trouvai la capsule tapisée de cristaux dorés qui avoient la finesse de la soie, qui détonoient comme la poudre à canon, et qui, à mon avis, en auroient produit l'effet dans une arme à feu." (The next day, I found the crucible covered with golden crystals which had the fineness of silk, which detonated like gun powder, and which, in my opinion, would produce the same effect in a firearm.) Welter named picric acid amer (bitter): from p. 304: " ... je nommerai amer." ( ... I will name it "bitter".)
(1922) [1]History of the Great War - Surgery of the War, Vol. 1, Pg. 175.
Junqueira LC, Bignolas G, Brentani RR (1979). "Picrosirius staining plus polarization microscopy, a specific method for collagen detection in tissue sections". The Histochemical Journal. 11 (4): 447–455. doi:10.1007/BF01002772. PMID91593.