THE SHOEES OF BRITAIN. 41 



evaporated, it might be made sufficiently strong. 

 However, an ingenious chemical friend (the Eev. W. 

 Gregor) assures me he has procured a fine lake from 

 an infusion of it by means of alum." 



One or two species of the genus Porphyra are 

 brought to our tables, stewed under the name of 

 Laver, and are thought a delicacy. ]\Ir. Drummond 

 informs us that P. laciniata, called Sloke in Ireland, 

 is gathered during the winter months only, the fronds 

 being too tough in the summer. After being properly 

 cleaned, it is stewed with a little butter, to prevent 

 its getting a burnt flavour, and is brought to Belfast, 

 where it is sold by measure usually at the rate of five- 

 pence per quart. Before being brought to table, it 

 is again heated with an additional quantity of butter 

 and io usually eaten with vinegar and pepper. P 

 vulgaris is worthy of notice on account of the extreme 

 difficulty with which it is presei-ved in a herbarium 

 in a complete state : " not that there is any difficulty 

 in spreading and going through the other steps of the 

 process, but because when it has nearly arrived at the 

 last stage of drying, a moment's exposure to the air 

 will cause it to contract so instantaneously, that the 

 edges of the paper are immediately drawn towards 

 each other; and if attempted to be restored without 

 (he whole being first damped, the specimen tears 

 through the middle, and becomes of little value. Tlie 

 edges of the plant adhere strongly to the paper when 

 dry, or nearly so ; but the centre does not adhere at 

 all, and being as fine as gold-beater's leaf, though 

 having considerable strength, it at once loses the little 

 moisture it possesses, on coming in contact with the 



