110 ELEMENTS OF MATERIA MEDICA. j

Natural History . —It exists in both kingdoms of nature.

{a.) In the inorganized kingdom. —Yauquelin met with iodide of silverin a mineral brought from Mexico , and Mentzel found iodine in an ore ofzinc which contained cadmium. It has also been met with in an ore oflead— ( Journ. de Pharmacie, tom. xxiii.for 1837, p. 2!).) In sea-water it ?has also been discovered, where it probably exists as an iodide of sodium 'or of magnesium. Many mineral waters likewise contain it. It was 1detected by Mr. Copeland in the carbonated chalybeate of Bonnington. ”About one grain of iodine was found by Dr. Daubeny in ten gallons of \the water of Robbin’s Well at Leamington, in Warwickshire . In the old ;well at Cheltenham the quantity was not more than one grain in sixtygallons. In a brine-spring at Nantwicli, in Cheshire, there was about agrain of iodine in twelve gallons. In the sulphurous water of CastelNuovo d’Asti, iodine was discovered by Cantu. In some of the mineralwaters of Germany, Bavaria, and South America , it has also been de-tected—( Gairdner on Mineral and Thermal Springs, p. 27.) Fuchsfound it in the rock-salt of the Tyrol-— {Gin (din, Handbuch der Chernie.)

( b.) In the organized kingdom. —Of animals containing iodine I maymention the genera Spongia, Gorgonia, Doris, and Venus: likewise Sepia,the envelopes of the eggs of which contain it. An insect has been foundnear Ascoli, in Italy , which Savi has described under the name of Julusfcetidissimus, containing iodine. The animal emits, when disturbed, a ■yellow fluid strongly smelling of iodine, and which immediately strikes 'sthe characteristic violet colour with starch— ( British and Foreign Medical JReview for January, 1838, p. 163.) Recently iodine has been detected fin the oil of the cod’s liver— {Journ. Pharm. tom. xxiii. p. 501.) A very jconsiderable number of vegetables, particularly those belonging to the ]family Alg<e, yield it. The following are some instances : Fucus vesicu- ’■losus, F. serratus, and F. nodosus; (lig. 36, a,b, c.) Laminaria saccharina, i

Fig. 36.

a. Fucus vesiculosus. c. F. serratus.

b. F. nodosus. d. Laminaria digitata.

and L. digitata; (fig. 36 d) Halidrys siliquosa; Chorda Filum; Gelidiumcartilagineum; Haiyseris polypodioides; Phyllophora rubens; Rhodome-nia palmata; UlvaLinza; Porphyra umbilicalis; Padina Pavonia ; Gi-gartina Helminthocorton, and some of the marine Conferva ». )

It has been found in several species of phaenogamous plants, as Zos- b