222 CRYPTOGAMIA ALG.E. 



stinctively to migrate from the hills to the shore at the 

 ebbing of the tide to feed upon it. LIGHTFOOT mentions 

 that during severe snow storms, stags have been known to 

 descend from the mountains for the same purpose. He 

 also says that in some of the islands, the inhabitants cover 

 their cheeses with the ashes of F. vesiculosus, and thus sup- 

 ply the place of salt. In Jersey it is collected and dried 

 in July, and housed for winter fuel ; being likewise used 

 in smoke-drying pork, beef, and fish. 



Dr RUSSELL found the mucus of the receptacles to be a 

 very efficacious resolvent when applied externally to scro- 

 fulous swellings. He recommends the patient to rub the 

 tumour with these receptacles bruised in his hand, until 

 the mucus has thoroughly penetrated the part, and after- 

 wards to wash it with sea-water. The late discovery of 

 the existence of iodine in marine algae affords a good ar- 

 gument in favour of this practice. " The charcoal obtain- 

 ed by burning it in close vessels has in some places got the 

 name of Mthiops vegetabilis. It used to be considered 

 merely as a compound of charcoal and carbonate of soda, 

 and as such was neglected ; but it contains also iodine, and 

 since Dr COINDET'S discovery of iodine as a specific in 

 bronchocele and strumous affections, its effects are deser- 

 ving of being again studied." Dr DUNCAN. 



2. F. serratus, frond plane, dichotomous, dotted, the margin 

 serrated; ends of the segments when in fruit thickened, tubercu- 

 lar, orange. coloured LIGHTF. Scot. 902. WITH. iv. 99. NEILL 

 in Edin. Encycl. x. 19. HOOK. Scot. ii. 95. GREV. Alg. Brit. 15. 



TIab. On rocks, common. Spring. T/. 



This scarcely enters the river, though it may be found just 

 at its mouth. The Dutch cover their crabs and lobsters 

 with it to keep them alive, preferring it to any other sort 

 on account of the smaller quantity of mucus which it con- 

 tains. Our fishermen use it indiscriminately with the 

 preceding. 



* * Frond without a midrib. 



3. F. nodosus, frond compressed, dichotomous, swollen at inter- 

 vals into large vesicles, the sides beset at intervals with club- 

 shaped processes, single or clustered, turgid and yellow when in 

 fruit. LIGHTF. Scot. 9! 9, WITH. iv. 90. NEILL loc. cit. x. 18. 

 HOOK. Scot. ii. 94. GREV. Alg. Brit. 1G. 



