BULLETIN OF THE BUSSEY INSTITUTION. 257 
are so well adapted for being made into hay as sorrel. They dry 
with extreme slowness, and the presence of such succulent plants 
in mowing fields must be objectionable on account of the liability 
of carrying lumps of them to the stack or mow in a half dried state, 
to the injury of the hay proper. Indeed, it is not at all impossible 
that beside mouldiness and the moderate ‘‘ heating” which would 
be induced by moisture in the stack, the hay might sometimes even 
be set on fire by the undried leaves of certain weeds. A belief in 
the possibility of this result was long ago popularly current in some 
parts of England, as may be seen by referring to the heading 
‘* Fire-leaves ” in the Dictionary of English Plant Names, pub- 
lished by the English Dialect Society. It appears that the name 
fire-leaves is applied by the common people to certain succu- 
lent leaves which, as they think, are liable to set ricks on fire. 
In Gloucestershire plantain leaves, and in Herefordshire those of 
Devil’s bit (Scabiosa succisa) are called fire-leaves.* Perhaps the 
occasional presence of nitrates in such leaves may be one cause of 
their spontaneous combustion? On page 127 of volume II. of the 
Bussey Bulletin, I have mentioned a case that fell under my own 
observation, where purslane that had grown in a garden border 
was found to be highly charged with nitrates.t It is known that 
the leaves of many other kinds of succulent weeds which feed 
grossly may become charged with nitrates under favorable circum- 
stances, as when grown on very rich land in warm weather. 
The use of the young stalks of milk-weed as an article of food 
is mentioned in the ‘‘New England Farmer” for 1829, vol. 8, 
p- 61, and repeatedly in subsequent volumes. ‘Thus, in 1835 
(vol. 13, p. 373) ,{ an article quoted from the ‘‘ Baltimore Farmer ”’ 
contains the following statements : — 
‘¢ Milk-weed has long been used in Canada for culinary purposes 
as a substitute for asparagus. It is easily cultivated. ... When 
the young shoots are four or five inches from the ground, they may 
be cut and served up in the manner of asparagus. ... Parkinson 
received the plant from this country and cultivated it (in England) 
* «< Old Country and Farming Words,” p. 18. 
+ I notice that Lemery is credited with a similar observation, made some 
time during the first half of the last century. The presence of nitrates in 
many different kinds of weeds was observed by several of the European 
chemists who so carefully studied the theory and practice of nitrification 
about the time of the American revolution. 
t A good part of the same statement was repeated in the next volume of 
the ‘‘ New England Farmer,” 1835, 14. 117. 
