8 
tures is such as to prevent any attempt to rear 
them in company, and even then , it is only a 
certain portion of the silk which could be so 
employed, the rest being covered by the sticky 
exudation by which they entrap their prey. 
An examination of any good work, such as 
Macculloch’s Dictionary of Commerce, will 
give any one who wishes to inquire into the 
subject of silk manufacture, such fully and 
satisfactory imformation that I shall not say a 
word about it. I shall now briefly notice 
insects useful in dyeing. The Cochineal insect 
is, of course, of the greatest importance in this 
respect. To it we are indebted for our most 
brilliant scarlet and crimson tints. As 
a pigment, Carmine stands unrivalled 
in power and brilliancy, but as painters well 
know, it is open to a grave objection — that of 
its liability to fade. The man who could invent 
a way of making this splendid color permanent 
would confer a boon upon art itself. In con- 
sequence of the fleeting nature of thh color, 
painters who value their reputation must be 
content to use others, which, though less 
brilliant, are much more durable. Madder is 
found to be the best substitute, but as this is 
a vegetable product, I must not speak of it 
here. The color called lake is also a product 
of the insect world. The family to which both 
the cochineal and the lac insects belong is the 
homoptera, genus coccus, a very extensive one 
in this country and many others. This genus 
(coccus) is nearly allied to the aphides, and is 
of similar habits. Fixing themselves on one 
spot of the branch of a leaf of the particular 
tree to which they are attached, and sucking 
out the juices. Strange and wonderful chemistry 
that these juices should become so changed in 
their passage into or through these creatures, 
as to form in one a sugar, in another a wax, 
and again in another a resin or a dye. The 
whole body of the cochineal insect is permeated 
with the brilliant coloring principle. These 
singular insects feed upon the nopal, sometimes 
called the cochineal cactus. It is the female 
insect which yields the dye. The West Indies, 
Mexico, and some parts of South America, are 
its natural habitat. The collection of these is 
a very tedious and, probably, painful process. 
The plant being of a prickly nature, in fact, 
like the prickly pear, it is requisite to use 
great caution ; and, accordingly, they are 
brushed off into bags, and killed by dipping 
in boiling water : after which, they are 
exposed to the sun to dry them. When 
they look like dry shrivelled u , seeds, of a 
dull purple tint, mingled with a powdery 
bloom of a whitish cast. The lac insect is at- 
tached to various species of the fig tree. In 
consequence of its attacks upon these trees the 
small twigs or leaves become encrusted with 
what is at first called stick lack, which, after 
being boiled in water, lose their dark color, 
when they are termed seed lack. This, when 
melted and pounded out on a flat surface, 
hardens and becomes the transparent substance 
well known as shellac, so useful in var- 
nishes and French polish, and also as being 
the material employed in the manufacture of 
sealing wax, for which it is well suited on ac- 
count of its hardness. The beautiful Japan 
ware owes its durability to this substance, as it 
is not so readily scratched as other varnishes. 
The colouring matter called lake, though not 
nearly so valuable as cochineal, is largely used 
for dying purposes. It and shellac form a 
valuable article of commerce. In this country 
the wild fig is much infested by a species of 
coccus, which it is quite possible might be 
found to produce some such substance as what 
I have just described. 
Nearly allied to resin is wax, and here again 
comes the honey bee and its wonderful comb, 
fulfilling the requirements and solving the 
problem of the smallest quantity of material 
and the greatest strength, as well rs the most 
suitable form in the least compass. Wax has 
been used from time immemorial. After being 
bleached it becomes a wry beautiful substance, 
and is in this state used in the arts. It would 
be very difficult to enumerate the great variety 
of uses to which this article is adapted. It has 
long been the favorite source of artificial light, 
probably nine-tenths of the bees wax 
collected goes for this purpose. In Catho- 
lic countries the consumption must be 
enormous from the vast number of candles used 
in their religious services. The absence of 
smell and smoke render this material valuable 
when the use of gas would ever be objection- 
able, as in picture galleries, or in places where 
delicate works of art are exposed. The 
apothecary is largely indebted to this substance 
in the preparation of ointments, plaisters, Ac. 
From the great success which has attended 
the introduction of the domestic bee into the 
Australian colonies, it is not improbable that 
when an extensive agricultural population settle 
in this district, wax as well as honey will be- 
come a valuable addition to our exports. While 
mentioning beeswax in a medical point of view, 
I may briefly here introduce the Spanish fly, 
or, as it is scientifically termed, the cantharis 
vesicatoria, a species of beetle found in most 
parts of Europe, and rarely in England. There 
are several other species of the genuswhich possess 
the same properties. They are principally used 
for causing blister, a remedy very necessary, on 
the principle of choosing the least of two evils. 
They are also a powerful poison, and when used 
as a medicine are always employed with the 
greatest caution by the physician. It is said 
that when alive their presence can be detected 
at some distance , thus forming a guide to those 
who are in the habit of collecting them. When 
touched they emit a odour most offensive, and 
must be handled lightly, as their blistering 
powers are most potent. They are generally 
killed by exposing to the steam of vinegar, but 
sometimes by immersion in boiling water. The 
insect itself is very pretty, being of a shining 
green colour, and under the microscope forms a 
splendid object. Another insect not far re- 
moved from the cantharis is the meloe, or oil 
beetle. If these insects could only be procured 
in sufficient quantity they might be found of 
