594 
Supplement to the ''Tropical AgricullurisL" (Feb. 1, 1899. 
Assuming, then, that there were no avnilable 
ground-water to draw upon, an annual rainfall of 
17 inches, if it were all retained by the toil witli- 
in reach of tl)e plant, -would be entirely used up 
and evaporated by a crop of wheat during the 
period of its growth. 
It is further imijortant to remember that the 
plant begins to wilt long before the moisture in 
the soil is exhausted. 
The actual degree of dryness wliich causes the 
plant to wither varies according to the nature of 
the soil. 
It lias been proved that plants begin to wilt 
when the moisture in the soil fall? below one-third 
(about) of the quantity which the soil is capable of 
absorbing. Thus in an average loam which is 
capable of absorbing 50 per cent, of its own 
weight of water, plants will begin to suffer the 
effects of want of moisture when the amount of 
water in the soil falls mucli below 17 per cent. 
A sandy soil, on the other hand, may contain as 
little as 8 per cent, moisture before plants grown 
in it will begin to wilt. 
It is found, further, that plants thrive best 
when the quantity of water present in the soil is 
about half that wliich the soil is capable of absorb- 
ing. 
It may be interesting to state the capacity for 
Yvater — that is, the amount of water whicli the 
soil is capable of absorbing for different classes of 
soil : — 
Class of Soil. Capacity for Water. 
Sand '{o per cent. 
Loams ... ... ••• 50 „ „ 
Heavy Clay 00 „ „ 
TureClay 70 „ „ 
Garden mould 90 to 100 percent. 
Pure humus... ... ... 180 „ 
« — 
FEUIT EVAPORATOR. 
Among the many makes of evaporators in the 
market, it may be said that with the exception of 
one or two they all come under three heads . the 
Tertical type with the trays placed directly above 
cue another, the horizontal type, and the inclined 
type. The vertical sorts were first introduced, 
but it seems as though they were now falling into 
disuse, owing to better results being uniformly 
obtained from those which work on the horizontal 
and inclined system respectively. 
In all evaporators of the vertical and horizontal 
patterns the trays are necessarily placed one above 
the other, so that the steam form the lower trays 
ascends, and in so doing passes through and around 
all the trays above them. The danger from this 
is cooking or soddening the fruit. These results 
•when they occur are most disastrous, because the 
Topours expand, and finally burn the cells of the 
fruit, causing, by exposure of the contents, acidifi- 
cation and oxidisation, also dispelling the essential 
oils, to the retention of which aroma and flavour 
are due. In other words, the product is deprived 
of the attributes upon which excellence of quality 
depends. 
in evaporating fruit, one thing that must always 
be remembered is that the object to be attained is 
pot only to make the fruit keep, but also to retftiu 
the properties lor which it is valued- This can 
only be attained by withdrawing the water con- 
tent"!, and at the same time converting a portion 
of the starch into sugar in as bhort a time »s 
possible without boiling tlie fruit. The quicker 
the watery portion i* removed from the fruit the 
richer and the more durable itn taste will be. 
Another important point to be remebered is that 
the more completely the oxygen (f the uir is ex- 
cluded during the process, tlie more perfectly will 
the fruit retain its colour. Rapidity of Che drying 
process sometimes increases the content of sugar by 
25 per cent, and thi* increase is in exact proportion 
to a slower or quicker evaporation of the content 
of water. 
This is why evaporated fruit yields better 
results in weight than can be obtained by sun 
drying, because in the process of evaiK)ralion a 
portion of tlie contained water, which otherwise 
would be lost, is retained by combining with the 
Etarcii to form glucose, while the carbonic acid, 
whicli is always lost in the sun-dried fruit, is 
retained in its natural combination with the 
other substances composing the fruit. Hence it 
IS heavier, and those profitable and lienlihful 
chemical changes being all in accordatice with the 
laws of Nature will certainly take place if the 
necessary conditions of heat and air are properly 
applied. Otlierwise the operator will liave quite 
a different product, and no matter how good the 
fruit may be. or how perfectly bleaciied, true 
evaporation will not be obtained, and no matter 
how deceptive the fruit maybe in its colour or 
fancy packing, it will not stand the lest of long 
keeping in various warm or damp climates. The 
natural starch, gluten, and nlliumen of the fruit, 
instead of having been cured and made indestruc- 
tible by the chemical changes w hich constitute the 
difference between the evaporated and the dried 
fruit, will absorb moisture and additionol oxygen 
from the air; will increase in bulk, and be attacked 
by mould ; finally ending in sourness and decay. 
TELEGOXY OR ATAVISM. 
Telegony may be defined as the science of remote 
influence in the reproduction of species. The 
question it involves maj- be said to be: Does the 
first impregnation of the ovaries influence several 
or all the subsequent progeny of the female!' 
Thi^ knotty problem Prof, Cossar Ewart of 
Edinburgh set himself to solve single-handed. It 
is needless to state that the experiments conducted 
by him are of the highest importance to stock- 
breeders of every class, while as may be imagined 
they involve considerable difliculty and expense. 
The influence of tlie first impregnation so far as 
colour was concerned has been more or less 
apparent, but whether similar results followed 
with regard to other and more important charac- 
teristics has never been demonstrated. 
It was with horses that Professor Cossar Ewart 
decided to experiment, and to find a clear issue he 
secured a Burchell zebra stallion to mate with 
mares, as the stripes of the zebra would form the 
best', groundwork. The stripping, if it occurred in 
subsequent progeny, would be the characteristic 
to first exhibit itself, and the easiest to detect. 
