A large party of some of the friendly tribes, with their wives and children, repaired to the city on a visit of duty to the Governor, General Rosas, and had not been there long when some of them were attacked with small-pox, amongst the rest, one of their principal Caciques. As usual, the sufferers were immediately abandoned by their own relatives, and might have died like dogs, had not their more civilised friends taken charge of them, for which the poor wretches were abundantly grateful; but their surprise was without bounds, when the Governor himself, who had a regard for the old Chief, went in person to visit him. General Rosas did not fail to remark the strong impression created by his visit, and saw at once the advantage to which it might be turned. Ordering the astonished Indians to be brought before him, he showed them the mark upon his own arm, and fully explained to them the nature of the secret which had enabled him to visit their dying Cacique with impunity. The result was, that nearly 150 of them, including some of their Caciques, Catrieu, Cachul, Tetrué, Quindulé, Callinao, Toriano, and Venancio, with their wives and children, were vaccinated on the spot at their own earnest solicitation; and great was their childish delight on finding, in due time, the appearance of the disorder upon their arms, which they were fully satisfied would prove an infallible charm against the worst powers of the Evil one. The impression created by this interesting occurrence will not be easily effaced, and, although subsequent events may have unfortunately delayed for a time the further propagation of this inestimable blessing amongst the Indians, I have little doubt that it will again be sought for; and who can say that, with good management, it may not be converted into a means of domiciliating and reducing to Christianity the remnants of a race, who, in their turn, might repay with productive labour their benefactors a hundred fold? I must not close this chapter without adding that, notwithstanding what I have said as to the effects of the climate upon some constitutions, the people in general live to a good old age in perfect enjoyment of their mental as well as bodily faculties; and that instances of longevity are common, the following extracts from the several population returns will sufficiently prove:-- "In the census of 1778, 33 cases are quoted of individuals then living in the city, aged from 90 to 100; and 17 of from 100 to 112." In the tables of mortality for 1823 and 1824, 58 persons are said to have died between the ages of 90 and 100; 6 between 100 and 110; 3 between 112 and 116; 1 of 128, and another of 130. The two last were females. FOOTNOTES: [16] Meteorological Tables will be found in the Appendix. [17] The following letter, received from Buenos Ayres after my own departure, gives an account of one of these visitations. It is dated "Buenos Ayres, 11th February, 1832