The Delta of the Parana 177 



Italian, who had purchased a place for himself in the 

 lowlands, which he had improved by building a house 

 and outbuildings, and where he had sunk an artesian 

 well to get a supply of good drinking-water. To his 

 amazement when the well began to flow it yielded water 

 full of gas. We went to the well, which was discharging 

 a constant stream of clear water through a bent iron 

 pipe. The water was running through a number of tin 

 gutters into the river. Dr. Roth struck a match and 

 held it above the water. Flames instantly arose and 

 for twenty feet the stream was covered with coruscating, 

 lambent tongues of fire. To one familiar with the great 

 gas-wells of western Pennsylvania it appeared a very 

 tame little affair, but it was interesting to see how steady 

 was the flow of the gas. It undoubtedly was marsh-gas, 

 which had accumulated in the ground. The soil of 

 these alluvial islands is rich in decomposing vegetable 

 matter, and in places is almost as black as peat. The 

 formation of marsh-gas in great volume is what might 

 be anticipated from existing conditions. Dr. Bade 

 collected a number of samples of the gas for analysis. 

 Samples of the water were also taken. While the chem- 

 ist and the geologist were attending to these matters, 

 the botanist and the entomologist started out for a tour 

 of exploration through the clearing, which showed the 

 marks of having quite recently been overflowed. Deep 

 drainage ditches had been run in different directions. 

 Between them on the land which had thus been partially 

 dried young orange and lemon trees had been planted, 

 and an extensive vegetable garden had been laid out. 

 The small son of the owner accompanied us. Butter- 

 flies were not numerous, though the sun was warm 

 enough to entice them from their hiding-places. We 

 caught some specimens of Eresia anieta and Eresia 



12 



