STEUCTUEE AND COMPOSITION OF A BASALT FEOM BONDI. 217 



example, I have a reliable record of a white pine post, twenty 

 inches in diameter, put into the ground near Wellington, the soil 

 infested with white ants. It was removed after thirty years and 

 was quite sound, except sap-wood, and of the consistency and 

 colour of iron. It is a capital timber for house building pur- 

 poses, but is rarely used in Sydney, owing to the expense of 

 bringing it so far by rail. 



I failed to find a single instance recorded in the western districts 

 where white ants attacked the timber after it was dry, and the 

 majority of the houses etc., round the towns of Dubbo and Well- 

 ington are built of this timber. It is also forwarded for upwards 

 of a hundred miles by rail for building purposes, and invariably 

 gives satisfactory results as long as the black variety is not used. 



On the STRUCTURE and COMPOSITION of a BASALT 

 from BONDI, NEW SOUTH WALES. 



By Rev. J. Milne Curran, f.g.s. 

 [With Plates IX. - XII.] 



[Read before the Royal Society of N. 8. Wales, July 4, 1894.~] 



Contents. 

 I. — Introductory. 

 II. — Previous observers. 

 III. — Locality and occurrence. 

 IV. — Macroscopic examination. 

 V. — Chemical analysis. 

 VI. — Microscopic structure. 

 VII. — Conclusions. 



Introduction. 

 There is at the present time very little information available 

 as to the microscopic structure and the chemical composition of 

 our tertiary basalts. A glance at the geological map of New 



