ON A DIRECT METHOD OF OBTAINING IODINE. 
347 
The sea-weed being collected in heaps, may be suffered 
to drain itself of the sea-water mechanically retained about 
it. As this will occupy some hours, the time may be em- 
ployed by women and children in trimming the stalks of 
the tangle (Laminaria digitata) of leaves and roots, and 
arranging them ready for the turnip-cutter and other opera- 
tions, as stated above. The whole of the remainder may 
then be conveyed into old hogsheads, in a sheltered spot 
near the beach, and allowed to ferment ; the succeeding 
operations having already been described. A quantity of 
liquid is now assumed to have been collected, to which is 
added commercial hydrochloric acid, until a very marked 
acid reaction is obtained ; a solution of ordinary chlorinated 
lime is then added, to disengage the iodine, taking especial 
care not to use an excess. A very little practice will de- 
cide the quantity [necessary, as the brown color of the 
liquid will increase up to a certain point, and the smallest 
addition of chlorine, when this has been attained, will di- 
minish its intensity. Having thus liberated the iodine, it is 
precipitated with the prepared starch diffused through water, 
continuing its addition until it is no longer rendered blue by 
the iodine. The remainder of the process consists in de- 
canting the fluid portion, and straining the residuum, which, 
when dry will be immediately available to the iodine manu- 
facturer, and from which the iodide of potassium may be 
formed by the addition of sulphuret of potassium, or other 
appropriate means. The fluid portion being rich in potash, 
soda, and magnesian salts, will form a most important con- 
tribution to the liquid manure-tank, or may be thrown over 
the compost in the farm-yard, with the additional advan- 
tage of fixing the ammonia through its excess of hydrochlo- 
ric acid. The cakes of cellular tissue should be stored in a 
dry place, and made use of as fuel for steaming turnips,and 
other similar operations, taking care to preserve the ashes ; 
these should also be lixiviated, and thus every particle of 
iodine may be saved. 
