110 BRITISH SEA- WEEDS. [3Iela)wsj)ermea;. 



having the same medical virtues, and answering well as a 

 dentrifice, by not only removing tartar from the teeth, but 

 also correcting laxity in the gums. We have also lately 

 learned, that, Avhen the vesicles are put for two or three 

 weeks in rum or in spirits of wine, the tincture thus formed 

 has been found very efficacious as an embrocation for re- 

 moving rheumatic pains. 



The great use, however, now-a-days, of this weed along 

 with others, is in the manufacture of kelp and iodine; but 

 of this we have already spoken. 



2. Fucus CERANOiDES, Liii/i. This is sometimes called 

 Homed Fucus. It resembles the preceding, but it is much 

 thinner, and more transparent ; the midrib is more distinct, 

 and the leafy part is narrower ; althougli it is a more 

 graceful plant than Fucks vesiadosus. Some have tliought 

 that it is only a variety of F. vesiculosus caused by its grow- 

 ing where there is a copious admixture of fresh water; but 

 I have seen it where there was no supply of fresh water. 



It is common in many places in Scotland, but is less 

 common in England. It grows on rocks in sheltered bays, 

 and is perennial. 



3. Fucus SERRATUs, Limi. Serrated Sea-weed. (Plate I. 

 fig. 1. Portion of frond.) 



