17 
Precaution .—The only precaution needed is that the apparatus be 
placed so that there shall be no danger of its getting upset, and that 
only heat enough be applied to boil the sulphur, for, if by any accident 
the sulphur should catch on fire, it would destroy all the plants in the 
house very quickly. 
Suggestion .—It has been suggested that if the pipes are painted with 
linseed-oil and sulphur two or three times each year, similar good results 
would follow. It has long been the practice to paint greenhouse pipes 
with a mixture of lime and sulphur, but the results have not always 
been satisfactory, and the above suggestion may be open to the same 
objection, although we know of no carefully recorded experiments in 
the use of linseed-oil and sulphur paint. 
LETTUCE MILDEW.* 
When grown at a temperature above 40° F. at night, 55° F. in 
cloudy, and 70° F. in sunny days, lettuce under glass is often ren¬ 
dered unprofitable by the attack of this disease which causes the lower 
leaves to decay, and often the whole plant to die quickly. Other con¬ 
ditions may in a measure aid in bringing on the disease; for instance, 
anything that may cause a weak leaf-action of the plant, too much water 
in the soil, and too much moisture in the house, especially during the 
night. 
REMEDY. 
Evaporated sulphur proved beneficial, but not wholly preventive, in 
fact, only preventive conditions were found satisfactory. .These condi¬ 
tions are: 
1. A lower temperature at night than during the day, i. e., ranging 
from 35° F. to 45° F. at night to 50° F. to 70° F. during the day. In 
sunny weather the temperature may run 10° to 15° higher than on 
cloudy days. 
2. Perfect drainage of the soil. 
3. A house naturally dry, light, and airy. 
4. An abundance of plant-food in a light porous soil. 
Should the plants not start into a vigorous growth soon after trans¬ 
planting, the application of fine ground bone, one-half pound to a square 
yard, and 2 ounces of nitrate of soda to the same space, will give remark¬ 
able results. 
Suggestion .—While it is possible by close and constant attention to 
provide conditions for the successful growth of both the rose and lettuce 
under glass, such care and attention adds very materially to the cost 
of the products, and some means should be devised to destroy the germs 
* Peronospora ganglifornm , Berk. 
Q 
22161—-No. 1 
