MISSOURI BOTANICAL GARDEN BULLETIN 127 
Ammonium sulphate, though sometimes used in small 
quantities as a fertilizer, in larger amounts mixed with such 
inert material as sand, has been applied successfully upon 
lawns for the destruction of broad-leaved weeds. This chem- 
ical generally forms the basis of the commercial “lawn sand” 
and when spread upon the lawn checks the growth of all 
vegetation. The grass soon recovers, however, and through 
the stimulus received, produces luxuriant growth, choking 
out the weeds. 
For walks, roads, tennis courts, and all places where com- 
plete and lasting extermination of all plant life is desired 
other chemicals are used. The most important of these is — 
arsenate of soda. This is a very active poison and care must 
be exercised in its use. Two pounds to ten gallons is the 
formula employed. The solution may be applied with a 
watering can, using care not to get too close to valuable trees. 
_Carbolic acid is a very powerful and quick acting weed 
killer, but its effects are not as enduring as those of the 
arsenical solution. The formula is one pint to four gallons 
of water. Salt may also be used in the form of hot brine, 
the solution being strong enough to show crystals forming ~ 
on the surface. Better than carbolic acid or salt, however, 
for the destruction of woody plants, like poison ivy, is caustic 
soda (either sodium hydrate or sodium hydroxide). It 
should be applied hot in practically a saturated solution, dur- 
ing dry weather. After the destruction of the weed the soil 
should be thoroughly watered in order to wash out the soda 
and permit other vegetation to grow. 
_ In general, complete and permanent eradication of weeds 
is an economic impossibility, because they have gained a 
world-wide distribution and are found in waste places from 
which they are readily disseminated. : 
NOTES 
Volume III, Number 1, of the Annals of the Missouri 
Botanical Garden has been issued with the following 
contents: 
“Rhizoctonia Solani in Relation to the ‘Mopopilz’ and the 
‘Vermehrungspilz.’” B. M. Duggar. é 
“The Texas Root Rot Fungus and Its Conidial Stage. 
B. M. Duggar. : 
“Cabbage Yellows and the Relation of Temperature to Its 
ceurrence.” J. C. Gilman. ee yee os 
“Monograph of the North and Central American Species 
of the Genus Senecio—Part II.” J. M. Greenman. 
