292 



hundred pounds of vegetable organic impurities (in the mil- 

 lion gallons) derived no doubt from a marsh situated higher 

 up the slope of the hill, and about a quarter of a mile off, or 

 from truck farms in the same direction a half mile distant. 

 The drainage seems to break down, tlirough the loam and 

 clay cover, into the rock, and lind its way by the bed-plates 

 or cleavage-planes to the well. 



Professor Frazer adduced an instance where the water of 

 a well at least forty feet above the level of the Jenny Jump 

 Mountain Great Marsh, in Northern New Jersey, was made 

 poisonous in hot dry seasons especially, by the upward perco- 

 lation of marsh water. 



Dr. Cresson said that in the dryest times the subsoil on the 

 heights of Broad Mountain in Schuylkill Co. Pa. was 

 always kept damp by upward percolation. 



Professor Frazer described his observations at a recent 

 visit to the Bamfordville Zinc Works in Lancaster Co. Pa. 

 a mile east of Landisville, superintended by Mr. Spilsbury. 

 The deposit is of great interest to the geologist as well as 

 profit to the owners. Instead of being a carbonate, or silicate, 

 or mixture of these two species of zinc ore, as at Saiicon 

 near Bethlehem, and in the "Western States, it is a sulph- 

 ide, a very light yellowish brown zincblende, sometimes 

 quite colorless. 



He described the process of treating the ore by crushing ; 

 bolting into four or five grades of fineness ; jigging, or as to 

 the finest grade huddling ; and immediately roasting while 

 wet, fresh from the jig. By using the wet material Mr. Spils- 

 bury claims that he desulphurizes more readily. The roasted 

 ore is then retorted with fine anthracite dust, and to the 

 mixture Mr. Spilsbury adds 1 to 1. 5 per cent of salt, claim- 

 ing to get thereby 5 to 6 per cent more zinc from the ore than 

 he could without the use of the chloride. Professor Frazer 

 was desirous of obtaining the opinions of experts on the two 

 points thus observed. 



[Continued on page 333.] 



