614 
THE TROPICAL AGRICULTURIST. [January 2, 1882. 
USE OF SMALL BIRDS IN DESTROYING INSECTS. 
A correspondent writes : — In sending you the accom- 
panying cutting from a very old number of the Saturday 
Magazine, I wish to mention that a magpie (the com- 
mon Ceylon species) * has made a nest under the eaves 
of my office room, and I observed that in 30 minutes 
the parent birds have fed the young ones seventeen 
times, and all the food(grubs and caterpillars I believe)have 
been got from my flower garden, chiefly from the rose trees. 
We would say a word or two respecting the benefits 
and injuries imputed to Sparrows, Linnets, and other 
small birds. That they are occasionally mischievous 
cannot be denied, though its but fair to add, that they 
also, like the Rooks before mentioned, repay us by a 
considerable balance of good. That the Bullfinch feeds 
on the buds and seeds of trees, there can be no doubt, 
and that the Chaffinch, though by many considered as 
a pure feeder on insects, does the same, particularly 
in early Spring, when he inflicts ruinous injury on the 
sprouting crops of several plants, is equally true. Spar- 
rows, too, burrow in our stacks, and consume a cert- 
ain quantity of corn ; not, indeed, in the same serious 
quantities that another bird does, called the Snow- 
Bun 'in; : these birds, in hard Winters, come from the 
north in prodigious flocks, and, where they take up 
their quarters, become quite a nuisance ; not so much 
by what they consume, as by what they destroy ; which 
they do thus. In search of grain they frequent the 
stack, and then seizing the end of a straw, deliberately 
draw it out. To such a degree has this been done by 
them, that the base of a rick has been found entirely 
surrounded by the straw, one end resting on the ground, 
the other against the stack, as it slid down from the 
top, and as regularly placed as if by hand, and so 
completely was the thatching pulled oft, that it was 
found necessary to remove the corn. 
That some guess may be formed of the possible 
extent of good or evil occasioned by small birds, we 
annex the result of our own observations, on the pre- 
cise quantity of food consumed by certain birds, either 
for their own support or that of then- young, remark- 
ing at the same time, that the difference observed in 
the instances, may be partly accounted for by the 
different quantity of food lequired by young birds, at 
different periods of their growth. 
Sparrows feed their young 36 times in an hour, 
which, calculating at the rate of 14 hours a day, in 
the long days of Spring and Summer, gives 3,500 times 
per week ; a number corroborated on the authority of 
another writer, who calculated the number of Cater- 
pillars destroyed in a week to be about 3,400. — Red- 
starts were observed to feed their young with little 
green grubs from gooseberry-trees, 23 times in an hour, . 
which, at the same calculation, amounts to 2,254 times 
in a week ; but more grubs than one were usually im- 
ported each time. — Chaffinches at the rate of about 35 
times an hour, for five or six times together, when they 
would pause and not return for intervals of eight or. 
ten minutes : the food was green Caterpillars. — The 
Titmouse 16 times in an hour. 
The comparative weight consumed was as follows : — 
a Greenfinch provided with 80 grains, by weight, of 
wheat, in 24 hours consumed 70, but of a thick paste, 
made of flour, egg, &c, it consumed upwards of 100 
grains. — A Goldfinch consumed about 90 grains of Canary- 
seed in 24 hours. — Sixteen Canaries consumed at the 
average rate of 100 grains each in 24 hours. 
The consumption of food by these birds compared 
with the weights of their bodies, was about one-sixth, 
which, supposing a man to consume food in the same 
proportion to his weight, would amount to about 25 
pounds for every 24 hours I 
* Winch 1.1 nol si niagpir ;il all, bui. our chief Ceylon song- 
ster, .villi a voice like that of Annie Lawrie, "low and .sweet." 
" Spotted robi 1 " seems more appropriate than " magpie" 
;ip|,lie<l liy Europeans to tliis the " dayal bird " of the Sinha- 
lese, 1 bo rMpHychus saularis, Linn., of ornithologists.— Ed. 
INCREASING FARM PRODUCTIVENESS BY 
ARTIFICIAL MANURES. 
(Field, 15th October 1881.) 
Probably there is no book of recent publication which 
deserves more attentive study from British farmers than 
that of the French chemist, M. Ville, on artificial manures; 
inasmuch as he attempts to show that by their employ- 
ment in larger quantities than ordinary fanners have 
usually applied them, and according to the formulae which 
he prescribes, the occupiers of high-rented, hca\ily-taxed 
lands in Europe would be able to face American com- 
petition, and, if not securing large profits from their 
business, at least escape from being submerged by that 
wave of ruin, against which the husbandry of the old 
world cannot have too many breakwaters. The argu- 
ment of M. Ville in enforcing his theory is lucid and 
logical throughout, and no one can deny that he fortifies 
it very strongly with figures and facts; still, the ques- 
tion which he lays open for inquiry is too vast and 
momentous for a ready solution to be arrived at, capable 
of satisfying the general public, without experiments 
being tried over and over again under a variety of 
circumstances as regards soil and climate especially. 
For this reason the book cannot be too much read, as 
it seems peculiarly desirable that practical tests should 
be extensively applied, to prove how far its teaching 
can be vindicated. 
The point is worthy of profound consideration that 
we have already in England one of the grandest tests 
for the system advocated by M. Ville, in the peculiar 
method of corn growing which has been pursued for so 
many years by Mr. Prout, of Sawbridgeworth. To many 
also the success of the latter gentleman amounts to 
the best possible confirmation of the truth of M. Ville's 
principles which they could have. Mr. Prout employs 
artificial manures on an extensive scale indeed, being 
to the extent of 50s. an acre on an average per annum 
for his entire farm of 450 acres. He has written a 
book, in which he claims that by making this outlay 
he has been enabled to grow grain crops year after 
year on the same land, and secure a far better profit 
in so doing than the best and most fortunate of English 
farmers are accustomed to realise; so that M. Ville's 
case may be considered proved so far, that under the 
circumstances of soil and climate which Mr. Prout has 
at Sawbridgeworth corn growing may be made remunerat- 
ive, even against the pressure of American competition, 
through the employment of artificial manures in larger 
quantities than they are usually bestowed. 
So far as root crops are concerned, they have been 
habitually increasing these to a turly enormous extent 
during the past forty years — ever since the importa- 
tion of Peruvian guano commenced, and the great 
Liebig made known his discovery which led to the uprise 
of the superphosphate manufacture. The cheapness of 
mineral phosphates also has rendered great facilities to 
be available in raising roots, and especially turnips, 
more economically and largely for stock-feeding, whereby 
more and better farmyard manure has been made, to 
nourish the succeeding corn crops. To such an extent 
has this been done that it is a very popular belief, 
entertained by a considerable section of British farmers 
who occupy light soils, that their lands can be kept in 
sufficiently high condition without the aid of any other 
artificial manures than the phosphatic ones employed 
for roots and green crops. Still, such farmers usually 
are heavy purchasers of artificial foods for stock, under 
cover of which a great deal of nitrogen is purchased in 
the form of oilcakes, &c, which, after passing through 
the bodies of the animals, finds its way to the soil. 
If by ordinary management and reliance on home 
made manures the value of the crops be only from 
£5 to £7 per acre, whereas by the employment of one 
pound's worth of artificial manure per acre they can be 
