Oct. 1833. GREAT DROUGHT. 157 



in the estuary of the Plata. All the small rivers became 

 highly saUne, and this caused the death of vast numbers in 

 particular spots ; for vi^hen an animal drinks of such water it 

 does not recover. I noticed, but probably it was the effect 

 of a gradual increase, rather than of any one period, that the 

 smaller streams in the Pampas were paved with a breccia of 

 bones.* Subsequently to this unusual drought a very rainy 

 season commenced, which caused great floods. Hence it is 

 almost certain, that some thousands of these skeletons were 

 buried by the deposits of the very next year. What would 

 be the opinion of a geologist, viewing such an enormous col- 

 lection of bones, of all kinds of animals and of all ages, thus 

 embedded in one thick earthy mass ? Would he not attribute 

 it to a flood having swept over the surface of the land, rather 

 than to the common order of things ? 



These droughts to a certain degree seem to be periodical ; 

 I was told the dates of several others, and the intervals were 

 about fifteen years. A tendency to periodical droughts is, I 

 believe, common in most dry climates :t such certainly is the 

 case in Australia. Captain Sturt says they return after 

 every ten and twelve years, and are then followed by excessive 

 rains, which gradually become less and less, till another 

 drought is the consequence. The year 1826 and the two 

 following were singularly dry in Australia, and the latter 

 were the first of the " gran seco.^^ I mention this, because 



* In the neighbourhood of the great towns on the shores of the Plata, 

 the number of bones strewed over the ground is truly astonishing. Since 

 our return I have been informed, that ships have been freighted to this 

 country with a cargo of bones. That cattle should be fattened on turnips 

 manured with the bones of animals that lived in the southern hemisphere, ■ 

 is a curious fact in the commerce of the world In the East Indies the 

 luxurious drink wine cooled with North-American ice, which in its 

 journey has twice crossed the equator! 



t Perhaps in every country, but the effect is more marked where the 

 mean annual quantity of rain is small. I have seen the trunk of an old 

 tree in England, in which the successive rings showed a tendency to 

 periodical increase and diminution of size; about every tenth ring being 

 small. See Mr. Babbage's Ninth Bridgewatcr Treatise. Note M. 



