COLLECTIONS AND RECOLLECTIONS. 273 
ways fall in rain at the same part. There is not a day throughout 
the year on which rain does not happen at some place, and the tro¬ 
pical winds, aided by the constant heat of the atmosphere in the tor¬ 
rid zone, would sufficiently account for the absence of rain during 
the chief part of the year in that climate, not to mention the im¬ 
mense fall of rain that takes place there in the winter months. 
There is another Theory of the formation of rain, depending on 
the fact, that the quantity of vapour capable of being diffused through 
the air increases in a greater ratio than the temperature of the air; 
and thus, whenever two masses saturated with vapour are brought 
into collision by the currents of wind, the atmospheric condensa¬ 
tion takes place, the mean temperature produced not being able to 
support the mean quantity of vapour. If the masses of air are not 
quite saturated with vapour, less precipitation of rain takes place, or 
perhaps none at all; and the warmer the temperature of the masses, 
the greater the precipitation; this accounts for rains in summer be¬ 
ing heavier than those in winter, and in hot countries heavier than 
in cold. By neither of the above theories would I wish to assert, 
that rain is formed in no other manner than is therein stated. The 
formation is very little understood as yet, and a great quantity, per¬ 
haps the most part of rain maj r be produced by electrical changes 
in the atmosphere of which we are ignorant, and of which in the 
present neglected state of science in this country, I am afraid we are 
likelv to remain. 
Nil Desperandum. 
Highgale Grove, April 10 ///, 1833 . 
ARTICLE IX. 
COLLECTIONS AND RECOLLECTIONS. 
Reaping Unripe Wheat.— In the year 1820, it was announced 
by M. Codes de Vaux, that corn reaped eight days before the usual 
time, was not only secured from the accidental loss by the scattering 
of the grains, but that the grain was fuller, larger, finer, and that it 
was not liable to the attack of the weevil. The produce per acre was 
more, and quantity of flour greater, from equal quantities of wheat. 
I should be very glad to know, if any experiments have been made 
in this country, and with what success; as it is a subject of the 
highest importance. C. C. C. C. 
London, April '2nd, 1833 . 
T 
