148 MARVELS OF THE ANIMAL WORLD 



wheels of carriages. The fat extracted from wool 

 is nowadays purified and used for various purposes 

 under the name of lanolin. Oil is obtained even 

 from the eggs of a species of water-tortoise or 

 terrapin, which inhabits the rivers of Tropical 

 America, and Mr. Bates, in his book The Naturalist 

 on the Amazon, tells us that about 18,000 gallons of 

 oil were obtained from these creatures and exported 

 from the Upper Amazon every year, even after 

 the inhabitants had reserved 6,000 gallons of the 

 fluid for their own use, the total yield representing 

 the product of some forty-eight million eggs. The 

 oil was extracted from the eggs by breaking up a 

 large number of them in a trough, and after stirring 

 the liquid mass and then leaving it exposed to the 

 rays of the sun, the oil would collect upon the 

 surface, when it was skimmed off, placed in recep- 

 tacles, and, finally, boiled over a fire. 



In former days it was the custom to catch rattle- 

 snakes in order to obtain their fat and convert it 

 into oU, and regular hunting expeditions were 

 arranged for that pvnpose, the reptUes being traced 

 to their winter sleeping -quarters, where they used 

 to congregate in immense numbers. Mr. Catlin 

 records a curious incident in coimection with one 

 of these hunts when a rattlesnake, having come 

 forth from its resting-place, was caught and employed 

 as a living bomb by attaching some gunpowder 

 and a time fuse to its tail. It was then sent back 

 from whence it had come, with the result that the 

 explosion which followed proved a far more expedi- 

 tious method of destroying the colony of reptiles 



