In 1827 the naturalisation of the cochineal was attempted in Corsica, but without success. During the same year the cochineal was introduced into the Canary Islands, but the inhabitants did not understand the importance of the experiment. They counted the cochineal among the number of noxious insects, and tried in all ways to rid themselves of it. It was only after results obtained by some more intelligent farmers, that the inhabitants of the Canary Islands perceived the profits they might derive. From that time its cultivation was extended, and after the year 1831 it increased rapidly. Thus, the cochineal imported from the Canary Isles in that year amounted to only 4 kilogrammes. In 1832 the amount was 60 kilogrammes, in 1833 it was 660 kilogrammes, in 1838, 9,000 kilogrammes, and in 1850, 400,000 kilogrammes. The French colonists in Algeria also tried to raise it. In 1831, M. Limonnet, a chemist of Algiers, collected some cochineals, and had the merit of first introducing the insect into the colony. On account of bad weather these first essays were fruitless, but it was not long before they were repeated. [Illustration: Fig. 93.--Branch of the Cactus, with Cochineal Insects on.] M. Loze, surgeon in the navy, undertook to introduce the insect again, and, with M. Hardy, director of the central garden of Algiers, gave himself up, with great intelligence, to the naturalisation and rearing of the cochineal in Algeria. In 1847 the French Minister of War, for the purpose of having the value of the Algerian cochineal fixed by commerce, caused to be sold publicly on the market-place of Marseilles a case of cochineal, the produce of the harvests of 1845 and 1846, from the experimental garden of Algiers, and which contained 17 kilogrammes of this commodity. Since that time the cultivation of this insect, the beginning of which was due to M. Limonnet, has rapidly developed. In 1853, in the province of Algiers alone, there were fourteen _nopaleries_, or cactus gardens, containing 61,500 plants. The Government at that time bought the harvests for fifteen francs the kilogramme. We have only pointed out in a general way how the cochineal harvest is conducted. We will now enter into some details on the subject. These insects are gathered when the females are about to lay, that is, when a few young are hatched. It is when the females are pregnant that they contain the greatest amount of colouring matter. When the harvest time has arrived, the rearers stretch out on the ground pieces of linen at the foot of the plants, and detach the cochineals from them, brushing the plants with a rather hard brush, or scraping them off with the blade of a blunt knife.