COFFEE CULTIVATION. 181 
would supply food for grub, prevent wash, save the 
unshaded earth from being baked, and when dug into 
the soil supply nutrition for the coffee. On the other 
hand as was stated the other day, our prevailing 
white weed is regarded as a serious rival to cofiee 
in its demands on the soil. A possible further rea- 
son for permitting weeds to grow is suggested to us 
in the following extract from the London Atheneum 
of January 24th :— 
<* QoemicaL.—Jan. 15.—Mr. Warren De La Rue, 
President, in the chair.—The following paper was read : 
‘Qn the effects of the growth of plants on the amount 
of matter removed from the soil by rain,’ by Dr. 
J. H. Prevost. Soil three inches deep was placed in 
two glazed earthenware pans, seventeen inches in dia- 
meter; on July 2lst four grm. of white clover seed - 
were sown in one, the other being blank. ‘The pans 
were exposed till October 4th; the drainage water was 
zollected and analyzed; that from the clover soil 
contained 48'1 grains of solid matter per gallon, the 
‘the other 220. The auther concludes that rain re- 
moves much more matter from an wuncropped than 
from a cropped soil.” 
It is pointed out, however, that the conditions of 
our soil znd rainfall are widely different, the latter 
often mechanically washing off the surface soil,—rather 
than percolating for any depth. 
Whether the present very unusual thunderstorms 
will have any effect on the prevalence of leaf disease 
is a subject worthy of observation in different districts. 
If we are to find an explanation of the wonderful 
spread of henileis vastatriz since 1869, in an attempt 
of nature to restore the balance to our atmosphere, 
by reducing -a ceuperfluity oxygen, than we might 
suppose electricity to come in as a great aid, and 
even as superseding the need for active fungoid life. 
But this is a mere matter of speculation, and many 
years of scientific observa'ion would be required to 
verify such an idea. For the present we must wait 
to see if Dr. Trimen and Mr. Ward can throw fur- 
ther light on the mystery surrounding the origin, 
eause and conditions of hemileia vastatrix, and above all, 
can tell us how to prevent or modify its attacks. 
COFFEE TREES IN 1870 AND _ 1880. 
- Commenting on our “‘Hints for the Consideration 
of Planters,” a gentleman of experience in coffee writes 
-as follows :— 
“The coffee tree of 1880 is not the same robust 
healthy plant that it was in the days prior to leaf 
3 ; 
