Complicating the restoration are two factors, one purely natural, the other economic and political.

He started up, and went toward the wood; but what was his surprise to perceive a purely natural phenomenon!

The smoothness of the horns, incidentally, is not a purely natural phenomenon.

No purely natural effort is going to effect his escape from this siege.

Such difficulties as we have mentioned have been purely natural obstacles.

However, three specific populations are noteworthy as having been generally accepted to be purely natural.

If it were a purely natural thunder-and-lightning storm closing in on them, he wouldn't have sounded any more put out.

Apparently he'd appeared out of thin air, as if by magic, so there wasn't much point in giving a purely natural explanation for his arrival.

Now we had solid evidence confirming the rumors that this was no purely natural beast.

Most people in the world have never seen a horse-even the purely natural kind is something of a rare animal.