(i.) The water being turned into blood cannot, of course, be taken literally, any more than when Joel speaks of the moon being turned into blood.[40] It refers to the reddish colour, which is often seen in the Nile about the end of June; though it is not as a rule sufficient to kill the fish, or render the water unfit to drink. And the mention of _vessels of wood and stone_[41] is interesting, as it was the custom in Egypt to _purify_ the Nile water by letting it stand in such vessels; and the writer evidently knew this, and took for granted that his readers knew it too, though it seems to have been peculiar to that country. [Footnote 40: Joel 2. 31.] [Footnote 41: Exod. 7. 19.] (ii.) Frogs are most troublesome in September. (iii.) Lice, perhaps mosquitoes or gnats, and (iv.) Flies, are usually worst in October. (v.) Murrain among the cattle, and (vi.) Boils cannot be identified for certain, but their coming on just after the preceding plagues is most natural, considering what we now know, as to the important part taken by mosquitoes and flies in spreading disease. (vii.) The hail must have occurred about the end of January, as the barley was then in the ear, but the wheat not grown up; and severe hailstorms have been known in Egypt at that time. (viii.) Locusts are known to have visited Egypt terribly in March, which seems the time intended, as the leaves were then young. (ix.) The darkness _which might be felt_ was probably due to the desert wind, which blows at intervals after the end of March, and sometimes brings with it such clouds of sand as to darken the atmosphere.[42] And curiously enough it often moves in a narrow belt, so that the land may be dark in one place, and light in another close by, as recorded in the narrative. [Footnote 42: I have noticed the same in the Transvaal, in particular a sandstorm at Christiana, on 20th October, 1900, which so darkened the sky that for about a quarter of an hour I had to light a candle.] (x.) The death of the _firstborn_, which occurred in April (Abib), was evidently not a natural calamity. But what is specially interesting is the statement _against all the gods of Egypt I will execute judgments_, without any explanation being given of what is meant by this.[43] It refers to the Egyptian custom of worshipping _living_ animals, the firstborn of which were also to die; but this would only be familiar to a writer in Egypt, since, as far as we know, such worship was never practised in Canaan. The agreement all through is most remarkable, and strongly in favour of a contemporary date. [Footnote 43: Exod. 12. 12; Num. 33. 4.] (3.) _In the laws and addresses._