144 
Sup2jlement to the Tropical Agriciuturist. 
[An;. 2, 1897. 
rnin.s, lie says, the grass on the “ Tharavas ” rotted 
under a mixture of sea and rain water, and was 
converted into a luoss-like substance which the 
horses used to eat while grazing. 
The jyndical Officer, however, w'rites as fol- 
lows ; — “ The exciting cause of this disease, I 
believe, i.s change of .‘■easou, — a season of plenty 
of rain and pasture changing to a season of 
drought.” 
The identification of the disease is an important 
matter from a veterinary point of view. It is not 
likely that this horse plague at Mannar is a new 
disease which has not been described in standard 
works on veterinary science. I am inclined totbink 
it is identical with what Prof. Williams culls Epi- 
zootic Pleurisy or Pleuro-pneumonia of the horse. 
The Professor says : “ In 1861 to 1862 this form of 
epizootic disease became very prevalent in the 
north of England, where it raged for many months, 
committing great havoc amongst horses of all 
kinds, but particularly amongst tho e most ex- 
posed to the vicis.'-itude.s of the climate. It has 
prevailed more or less ever since, both in town and 
country, more particularly amongst young korses 
and those removed from pastures into stables. *** 
Aliernations of heat and cold are undoubtedly the 
mo.M prolific causes, for the disease prevails mostly 
when the winds are cold and the heat of the sun 
more or less powerful. ” 
The treatment of this disease as recommended 
by Prof. Williams consists mainly of proper 
hygienic measures and nursing. He condemns 
the employment of the so-called heroic remedies 
such as purgatives, bleeding and blisters. Com- 
plete rest, warm clothing, comfortable hou.sing in 
a well-ventilated loose box, but aroiding draughts 
are specially recommended by him. During the 
premonitary fever the animal is to be allowed an 
ulmndant supply of cold water to drink with 
nitre dissolved in it. Bran mashes and linseed 
niashes are to be given to keep up-a laxative con- 
dition of the bowels, and these may be supple- 
mented with enemas when necessary. If the 
alternations of the temperature of the skin be very 
marked, two or three dose.'; of spirits of nitrous 
ether are to be daily administered in warm water. 
When the fever is high and the symptoms are 
acute, great benefit may be derived from ten minim 
doses’ cd Fleming’s tincture of aconite given two 
or three times a day. Vet. Surgeon Hayes is of 
opinion that the fever is of a malarious character 
and suggests treating it with quinine. 
Opium in the form of laudanum is recommraded 
to relieve the paiir caused by the inflarnmation of 
the pleura. The laudanum is combined with 
modmate quantities of linseed oil so as to prevent 
its constipating effects. 
Warm fomentation.s to the sides followed by the 
application of weak ammonia liniment will give 
great relief. As the local inflammation progresses 
the dose of fiitre given in the drinking water is to 
be slic'htly increased. From one to two ounces of 
this salt may be given in the twenty-four hours ; 
and when it causes excessive diuresis it must be 
lessened again or discontinued altogether. If, 
however, nitre fails to stimulate the kidneys suffi- 
ciently, a few doses of tincture of colchicum seeds 
will be’of great service. Vegetable tonics may be 
given in the latter stages or during convalescence, 
combined with carbonate of ammonia. 
If the appetite is much impaired, the horse mii.^^t 
have an allowance of milk to drink instead of 
water. If the milk is refused, the animal must 
have gruel, linseed tea, bay tea. &c ; but nothing 
in the shape of food mii-t be foictd upon it. 
Suj/pref^sion. — I’lof. IViLiam.s says : — “ When the 
character of the outbreak is mild the disease seems 
to be non-contagious; \\ hen violent or acute, it 
presents such marked signs of being contagious, 
that even tlie inost sceptical i.s foictd to believe 
in this method of propagation.” 
It is scarcely necessary, therefore, to add that, 
w'hen this disease assumes an epizootic form, isola- 
tion and segregation suggest themselves as im- 
portant suppressive measuies. 
E. T. HOOLE. 
Anuradhapura, 19th July, 1897. 
INSECT I’ESTS. 
{Continuer .) 
It is evident that one cannot make use of pre- 
ventive and remedial measures to the beat advan- 
tage unless he has some knowledge of the insects 
with which he has to deal and of their habits. The 
planter or cultivator is as a rule a very busy man 
and cannot be expected to affoid the time required 
for the study of the complex lines of his insect 
foes entirely by himself; but he should sufficiently 
acquaint himself with Entomology to be able to 
under.stand fully the reports on injurious insects 
which may be available to him. He should learn 
the names of his common insect foes, the charac- 
teristics of their attack and the different stages 
of life through which they pass, and he should 
confirm as far as possible the statements he reads 
by his own personal observations which is gener- 
ally quite an essay matter, and will aid him 
greatly to remember about the insects. Every 
insect has several stages in its life and is often 
much more easily destroyed in a stage that passes 
unrecognised, because the insect then does little 
or no damage, than in the stage when it is inju- 
rious. 
In general there are four distinct stages of ex- 
istence in the life of an insect : — the egg, the 
larva, the pupa, and the imago. These stages may 
differ so greatly from one another that those who 
are not acquainted with insects would never suspect 
their relationship. Until all the stages of an insect 
are known, it is not possible to say with absolute 
certainty at what period of its life the insect 
may be most easily destroyed. 
Such study as this constitutes economic ento- 
mology which might be defined as the study of 
insects injurious to the agricultural and other 
interests of man w'ith a view to discovering me- 
thods for preventing or checking their ravages. 
As a rule such study is laborious and surrounded 
without difficulties. Many years of observation 
are often required to trace out the round of life of 
a single insect. Progress is necessarily slow, and 
even in those countries w here most attention has 
been given to the subject comparatively few in- 
sects have been thoroughly studied. As might be 
expected the United States leads in the line of 
research. Her immense agricultural interels have 
forced her to it. The losses there have also been 
greatly in excess of any other country, owing 
