M. Pagenstuher, an apothecary in Berne, had already drawn attention to the oil and distilled water of the blossoms of Spiræa Ulmaria in a treatise which may be found in Buchner's Repertorium, vol. {{sc|xlix.} p.337. He there describes exactly almost all the combinations which are the subject of this Memoir; and had he made analyses of the elements with only a few substances, the real nature, not only of the oil itself, but also several decompositions and recompositions which it experiences would not then have escaped him.
M. Pagenstuher had the kindness to give me the oil for all the investigations, and also to communicate to me his observations made up to that time. All his experiments which were of any importance on the present subject are incorporated into this Memoir, so that in many respects the present work may be considered as undertaken conjointly with M. Pagenstuher. To facilitate the general view of the following experiments, a few of the leading results may be first stated.
The oil of the blossoms of the Spiræa Ulmaria is a hydracid; it consists of one eq. of a radical = C 12 H 5 O 4, and one eq. of hydrogen, which uniting with the radical forms an acid. If the hydrogen, which by uniting with the radical forms the acid, be oxidized by nitric acid, 4 additional eqs. of oxygen are taken up by the radical, thus forming the oxyacid of the same radical. Instead of 1 eq. of hydrogen, the radical can unite with 1 eq. of chlorine, bromine, iodine, or even of a metal. These latter combinations are also formed when the hydracid is made to act on metallic oxides. With ammonia, on the contrary, the hydracid unites without undergoing any change. From these combinations the following compounds result:
| C 12 H 5 O4 + H |
| C 12 H 5 O4 + CI |
| C 12 H 5 O 4 + Br |
| C 12 H 5 O4 + I |
| C 12 H 5 O4 + P |
| C 12 H 5 O4 + O4 |
| (C 12 H 5 4+ H) + N H 3 or ammonia. |
The radical is designated by the name Spiræoyl, or for the conve-nience of shortness Spiroil. Another name would have been chosen for it had not a similar nomenclature been already applied to another substance nearly allied to it. It is always doubtful policy to derive the name of a vegetable principle from the plant in which it is first discovered, for generally with great probability the same body may be found in other plants. Names which designate any principal peculiarity of the substance are therefore in such cases always preferable. One of the peculiarities of spiroil is its property of forming yellow compounds with oxygen, and with the metals, alkalies, and earths; a name therefore which had reference to this quality would have been very suitable. A name
