THE THERMAL SPRINGS OF SELANGOR AND MALACCA. 53 



Composition of Air close to Spring. 



Oxygen, 



... 20.870 



Nitrogen, 



... 79.060 



Carbonic Acid, 



... 0.070 



Hydrogen Sulphide, 



... trace 



100.00 



(Ozone or active Oxygen absent). 



Ammonia in air near spring, o.n parts in 1,000 parts by 

 weight. 



A sample of air was collected about i^ miles from the 

 spring, and the ozone in it determined. 



The mean result of the separate experiments was 0.000,0011 

 milligrams per litre of air. 



Composition of Rocks from the Spring. 



It has already been stated that the formations in the imme- 

 diate vicinity of the springs are granitic, the principal com- 

 ponent minerals being accordingly : — Quartz, Felspar, Mica 

 (Muscovite and Zinwaldite) and Hornblende. 



The average composition of the rock (from 6 analysis) is 

 shown below : — 



Silica, 74-3°% 



Alumina, ... ... ... 14.20,, 



Alkalis, ... ... ... 5.10,, 



Lime, ... ... ... 3.00,, 



Magnesia, ... ... ... 0.60,, 



Iron (taken as Ferric Oxide), ... ... 1.10,, 



Moisture, Oganic Matter, Manganese, &c, 1.70,, 



100. 00% 



Tin ore in varying though small quantities is found dissemi- 

 nated through the mass of some of the specimens. Gold was 

 absent in all the samples I took, with the exception of a piece 



