CRYFTOGAMIA ALG^. 907 



about feven feet wide, and three deep, lined 

 with ftones. In this pit a fire is kindled with 

 imall flicks, and the dried Fucits is laid upon it 

 by little and little, and burnt. When a fuffi- 

 cient quantity is confumed for the purpofe, and 

 burnt to a certain degree, it appears in the pit 

 like red-hot alhes. The operator then (to pre- 

 vent its being reduced entirely to afhes) with 

 an iron rake ftirs about brifkly this hot matter 

 from one fide of the pit to the other, mixing 

 it well together, till at length it begins to con- 

 geal, and vitrify. The falts being now all 

 melted, the matter is left to cool in the bottom 

 of the pit, where, as in a mould, it concretes 

 into a folid mafs, call'd KeJp^ which, when 

 cold, is broken out of the pit, and carried to 

 market for the ufe of the foap and glafs- 

 makers. 

 There is great difference in the goodnefs and 

 price of this commodity, and much care and 

 fkill required in properly making it. That is 

 edeemed the bed which is hardeft, fineft 

 grain'd, and free from fand or earth. — The 

 price of Kelp in Jura is ^. 3. 10 J. per ton, 

 and about forty or fifty tons are exported an- 

 nually from that ifland. So great a value is 

 fet upon this Fucus by the inhabitants of that 

 place, that they have fometimes thought it 



worth 



