The blacksmiths in the neighbourhood, with no other apparatus than their common forges, make it directly into wrought iron, which they use for all ordinary purposes.
Now, in supposing civilization to be transmitted from one country to another, we must measure it by the height of its lowest point, as we measure the strength of a chain by the strength of the weakest link.
The only civilization that the Mexicans can have received from the Old World must have been from some people whose cutting implements were of sharp stone, consequently, as we must conclude by analogy, some very barbarous and ignorant tribe.
From this point we must admit that the inhabitants of Mexico raised themselves, independently, to the extraordinary degree of culture which distinguished them when Europeans first became aware of their existence.

The curious distribution of their knowledge shows plainly that they found it for themselves, and did not receive it by transmission.

We find a wonderful acquaintance with astronomy, even to such details as the real cause of eclipses,--and the length of the year given by intercalations of surprising accuracy; and, at the same time, no knowledge whatever of the art of writing alphabetically, for their hieroglyphics are nothing but suggestive pictures.

They had earned the art of gardening to a high degree of perfection; but, though there were two kinds of ox, and the buffalo at no great distance from them, in the countries they had already passed through in their migration from the north, they had no idea of the employment of beasts of burden, nor of the use of milk.

They were a great trading people, and had money of several kinds in general use, but the art of weighing was utterly unknown to them; while, on the other hand, the Peruvians habitually used scales and weights, but had no idea of the use of money.
To return to the stone knives; the Mexicans may very well have invented the art themselves, as they did so many others; or they may have received it from the Old World.