‎"HASSENFRATZ, J.H. - THE HUMUS THEORY ANNOUNCED.‎
‎Sur la Nutrition des Vegétaux. Premier- Troisieme Mémoire. (all).‎

‎Paris, Rue et Hotel Serpente, 1792. 8vo. 2 contemp. hcalf. Spines gilt. Light wear to spines. In: ""Annales de Chimie"", tome 13 + 14. 336 pp. + 2 plates and pp. 335 + 2 plates. (2 entire volumes offered).Hassenfratz' papers: pp. 178-192, 318-330 (tome 13) and pp. 55-85 (tome 14). Stamps to verso of titlepages. Scattered brownspots, some leaves in vol. 13 with a faint dampstain to upper margins.‎

Reference : 48909

‎First printing of these 3 memoirs in which Hassenfratz set forth the ""Humus theory of vegetation"". From Hassenfratz' theory Thaer later derived his theoretical basis for plant nutrition.The volumes also contains Hassenfratz's importent paper on chemical affinities ""Explications de quelques Phénomenes qui paroissent contrarier les loix des affinités chimiques"", 1.-2. memoir, pp. 3-25 a. 25-38. Also papers by Pelletier, Vauquelin, van Mons, Berthollet, Fourcroy, Haüy etc.‎