DiS BRITISH GRASSES. 



the operation of the Scottish law to the coasts of Eng- 

 land, and imposing further penalties for its violation, so 

 that it was rendered penal not only for any individual 

 (the Lord of the Manor not excepted) to cut the bent, 

 but for any one to be in possession of any within eight 

 miles from the coast. " Excellent fences are formed of 

 reeds with the addition of posts and rails ; these to- 

 gether form a kind of panel, which can either be used 

 singly as a screen for fruit or other trees, or be united 

 with others, and so form a vegetable wall. The reeds 

 should be cut and dried, and then bound in bundles ; so 

 prepared, they fetch a good price in the market. They 

 are also used for laying plaster floors, and very exten- 

 sively for thatching. They are not, of course, worth 

 growing where a corn crop could be raised, but they 

 bring a good profit for waste ground. 



Various grasses have chemical properties of some im- 

 portance. Mr. Holland, in a very able lecture, demon- 

 strated the presence of a chemical substance called Con- 

 marine in Sweet Vernal Grass, to which it owes its per- 

 fume, which substance is also present in the TonquinBean, 

 Woodruff, and Melilot, and imparts to them a. similar 

 odour; from any of these plants this conmarine, or essence 

 of hay, may be extracted in the form of needle-shaped 

 crystals by dissolving in spirits of wine and then evapo- 

 rating the spirit. The conmarine has a very pleasant 

 perfume, but when heated it acts powerfully and pain- 

 fully on the brain. Mr. Holland suggests that the 

 peculiar affection called hay -fever is, in all probability, 

 really caused by this conmarine, which is given off in 

 great quantities by the drying hay, and, though dis- 

 persed in the air, may still float in sufficient quantities 

 to act painfully on the brain of those susceptible of its 



