wall, it actually blew itself back from the wall; and, as the wall was luckily strong enough not to be blown down, the lava kept blowing itself back till it had time to cool.  And so, my dear child, there was no miracle at all in the matter; and the poor people of Catania had to thank not St. Agatha, and any interference of hers, but simply Him who can preserve, just as He can destroy, by those laws of nature which are the breath of His mouth and the servants of His will.

But in many a case the lava does not stop.  It rolls on and on over the downs and through the valleys, till it reaches the sea-shore, as it did in Hawaii in the Sandwich Islands this very year.  And then it cools, of course; but often not before it has killed the fish by its sulphurous gases and heat, perhaps for miles around.  And there is good reason to believe that the fossil fish which we so often find in rocks, perfect in every bone, lying sometimes in heaps, and twisted (as I have seen them) as if they had died suddenly and violently, were killed in this very way, either by heat from lava streams, or else by the bursting up of gases poisoning the water, in earthquakes and eruptions in the bottom of the sea.  I could tell you many stories of fish being killed in thousands by earthquakes and volcanos during the last few years.  But we have not time to tell about everything.

And now you will ask me, with more astonishment than ever, what possible use can there be in these destroying streams of fire?  And certainly, if you had ever seen a lava stream even when cool, and looked down, as I have done, at the great river of rough black blocks streaming away far and wide over the land, you would think it the most hideous and the most useless thing you ever saw.  And yet, my dear child, there is One who told men to judge not according to the appearance, but to judge righteous judgment.  He said that about matters spiritual and human:  but it is quite as true about matters natural, which also are His work, and all obey His will.

Now if you had seen, as I have seen, close round the edges of these lava streams, and sometimes actually upon them, or upon the great bed of dust and ashes which have been hurled far and wide out of ancient volcanos, happy homesteads, rich crops, hemp and flax, and wheat, tobacco, lucerne, roots, and vineyards laden with white and purple grapes, you would have begun to suspect that the lava streams were not, after all, such very bad neighbours.  And when I tell you that volcanic soils (as they are called), that is, soil which has at first been lava or ashes, are generally the richest soils in the world—­that, for instance (as some one told me the other day), there is soil in the beautiful island of Madeira so thin that you cannot dig more than two or three inches down without coming to the solid rock of lava, or what is harder even, obsidian (which is the black glass which volcanos sometimes make, and which the old Mexicans used to chip into swords and arrows,