274 PROCEEDINGS OF SECTION B. 



ones ; and this glairy substance is largely composed of 

 varities of the diatomaceae. The drops of water falling 

 from the projecting cliff supply about 300 gallons in 24 

 hours ; this supply is caught in a tank, so that all risk of 

 surface contamination is avoided. The water as it issues 

 from the cliff possesses the normal temperature. On parts 

 of the cliff the tufa is quite dry and hard, and evidence is 

 seen of former flows, or it may be the present spring has 

 altered its place of exit from the underground channel. A 

 chemical examination of the water caught direct from the 

 drips gave the following results : — 



Total solids per gallon, heated to 130° C, were 182-56 grains. 

 These consist of — 



Silica -336^ 



Iron, Alumina, or phos- 

 phates ,.... traces 



Sulphate of Calcium 'G? 



Bicarbonate of Calcium 17"83 



Ditto MaOTBsium... 31-225, • ,, 



c 1 1 * f\/i • Vff rams per gallon. 



Sulphate ot Magnesuim, ' " r & 



with some chloride.... 11-13 

 Chloride of Sodium, with 



a little potash 120- 



Nitrates, calculated as 



Nitrate of Sodium -28 j 



The free ammonia and alluminoid ammonia amount to -007 

 and -008 grains per gallon respectively, showing the water 

 to be practically pure. The water is free from poisonous 

 metals. An examination for Lithia by wet. processes gave 

 negative results. Mr. Antill informs me that the volume of 

 the spring remains about constant in all seasons and weathers, 

 which fact points to a deep-seated origin, but I am inclined 

 to believe that the spring is a result of an extensive system 

 of surface drainage. The waters of the Stone Quarry Creek, 

 which takes its origin in the hills of the W'ianamatta shales, 

 are decidedly brackish, and nodules of limestone may be 

 detected on its upper slopes. It seems to me probable that a 

 part of the surface water finds its way into the creek, and 

 another part soaks into the soil till it reaches an impervious 

 bed in the Hawkesbury sandstones, and this part finds its 

 exit at the cliff mentioned above. 



The Jarvisfield mineral water is becoming a recognised 

 medicinal agent in Sydney. Several medical men have used 

 it with success. Mr. Antill informs me that apphcations for 



