338 ON A DIRECT METHOD OF OBTAINING- IODINE. 
that the intertropical parts of the country are favored'with 
a more constant supply of rain, as well as lower degree tem- 
perature, it is probable that they do not occur. 
American Journal of Science and Arts, July 1850. 
ART. LXXVI. — ON A DIRECT METHOD OF OBTAINING 
IODINE FROM CERTAIN SPECIES OF SEA-WEED ON THE 
LARGE SCALE, WITH A MODE OF PROCURING IT AS A 
SUBSIDIARY PRODUCT ADAPTED TO COAST FARMS. 
By George Kemp, M. D., 
Cantab., Fellow of the Cambridge Philosophical Society. 
The following paper contains the summary of a research 
on the above subject, made on the Isle of Man, at intervals, 
during the year 1847, 1848, and 1849 ; and, although dis- 
tinguished by many district features, the principles involved 
are equally applicable to all localities similarly circum- 
stanced. As a preliminary step, it may not be improper to 
remind the reader, that on all sea-coasts the marine vegeta- 
bles may be classified according to the depths at which they 
are found ; and for our present purpose it will merely be 
necessary to include them under two general classes, the 
shallow and deep water sea-weeds ; the former of these 
embracing such growths as flourish between high and low 
water-marks, and the latter such as are only, or principally, 
found from low water-mark to the depth of three or four 
fathoms. We instance the Fucus vesiculosus, F. serratus, 
F. nodosus and Halydrys siliquosa as specimens of the 
first of these divisions ; whilst the Laminaria digitata> 
L. saccharina and L. bulbosa will be sufficiently illustrative 
of the second, and have indeed furnished the principal ma- 
terials for the investigation on which we are about to enter. 
It may further be premised, that nature, equally provident 
and fertile in her resources, seems to have destined these 
