78 THE ANNUAL DOG MERCURY. 



of human habitations and uncultivated fields. If let alone, 

 it spreads with a dangerous rapidity, and invades every 

 garden which is not kept in the most exquisite order. 

 Still, we must not deal too harshly with it. It is not 

 altogether unfriendly to man. In truth, owing to its laxative 

 properties, it renders him invaluable services. The country 

 people have great faith in fomentations of Dog Mercury 

 and honey. Understand, we pray you, that not an atom of 

 mercury enters into it, despite its significant name; but a 

 decoction of the annual Dog Mercury, mixed with a little 

 thick honey, answers all the purposes of those lenitive 

 clysters which are so beneficial to excitable temperaments. 

 The leaves of the plant are eaten in Germany like spinach. 



Of the Mercurialis perennis Mr Sowerby writes : " This 

 plant was formerly used in medicine, but has long been 

 abandoned as a remedy. It is extremely acrid, and even 

 poisonous, though recommended in some old books as a 

 good pot-herb, probably from being confounded with the 

 annual species. When steeped in water, the leaves give 

 out a fine blue colour resembling indigo. This colouring 

 matter is turned red by acids, and destroyed by alkalis, 

 but is otherwise permanent; it might possibly prove valu- 

 able as a dye, if any means could be discovered of fixing 

 it, and the herb has been introduced into this work with 

 the view of drawing the attention of chemists to the subject ; 

 no experiments seem to have been lately made upon it." 



Let us now advise you how to distinguish our medicinal 

 plant from the " ill weeds" with which it loves to associate. 



