Why was the cochineal insect originally supposed to be a grain or seed?

Because, during the whole term of its life, it remains fixed to the spot where it first settled, and to the vegetable nipple of the nopal plant which feeds it.

Why are these insects propagated with such rapidity?

Because the nopal plant is inoculated with them, by being rubbed with a small portion of the young resembling blight, and, in proportion as the plant increases its leaves, it is sure to be covered with this costly parasite. When the plant is perfectly saturated, the cochineal is scraped off with great care. Plantations containing fifty or sixty thousand trees, growing in straight lines, may be seen in some districts of America. The quantity of insects annually exported from South America is valued at 500,000. The Spanish Government are jealous of its being naturalized elsewhere, while a reward of 6,000/. is offered by the East India Company for its introduction into our territories.* Cochineal has been transplanted to Java and old Spain, with great success, and on the island of Malta. The wild species of cochineal, or kermes,

*The duty on cochineal imported from British possessions is 2d.perlb., other places, 6d., and the amount for the year 1827 was 4,162/. 13s. 1 :d, was discovered about three years since among coffee plants and acacias in the Botanic Garden at Cambridge, where the gardeners called them " amelca bugs."

Why are the female insects the most valuable ?

Because they produce the best colour. They are in number to the males as three hundred to one. M. M. Pelletier and Caventon have lately found that their very remarkable colouring matter is mixed with a peculiar animal matter, like fat, and with different salts: they have obtained this colouring matter in great purity and called it carminium. Carmine is a triple compound of an animal matter, carminium, and an acid which enlivens the colour.

Why is fine cochineal of a grey colour, inclining to purple?

Because the grey is a powder which covers it naturally, a part of which it still retains; and the purple tinge proceeds from the colour extracted by the water in which it has been killed.

The important use of cochineal in producing a fine scarlet colour, is now well known. Long after its introduction, however, cochineal gave but a dull kind of crimson, till a chemist named Kuster, about the middle of the sixteenth century, discovered the use of the solution of tin, and the means of preparing with it and cochineal, a durable and beautiful scarlet. The immense consumption of cochineal in England is, in some measure, explained by the prevailing colour of our army clothing being scarlet.