SPECIMENS or FOSSIL WOODS IN NATAL MUSEUM. 369 



to agree perfectly with that of the sample of Water Boom wood 

 in the Museum, and very approximately with the sample 

 described bv Stone. 



(4) CHEMICAL COMPOSITION AND PHYSICAL PROPERTIES. 



At St. Lucia, False Bay and Port Durnford some of the 

 specimens from the lignite seam exhibited the transformation 

 of the wood into a jet-like substance. The various stages of 

 the transformation could be traced. The elements of the 

 w^ood are gradually converted under pressure into a compact 

 more or less homogeneous substance which is translucent and 

 brownish-yellow in section. 



Analyses of a typical piece of the lignite (PL XXVI, fig. 

 10) and of the jet-like substance (PI. XXVII, fig. 23) were 

 made in the (rovernment Laboratory, Durban, with the 

 results shown in the following table : 



Fossil wood. Port 

 Durnford. Mus. No. 232. 



Including 



the 

 moisture. 



Excluding 

 the 4.-61 

 per cent. 



moisture. 





f Water expelled at 



j 100° C. 



J Carbon . 



j Hydrogen 



I Oxygen l 



l^Nitrogeu ) 

 Silica 



Oxide of iron 

 Oxide of alumina 

 Oxide of lime 

 Oxide of magnesia 

 Phosplioric anhy- 

 dride . 

 Sulplutrie anhy- 

 dride . 



Per cent. 



r 



I 4-61 

 2 j 909 

 si 2-16 



[ 8-26 



7302 

 115 



0-30 

 0-.52 

 012 



019 



ti-ace 



99-42 



Per cent. 



9-53 

 2-26 



8-66 



76-57 

 1-21 



0-31 

 0-55 

 0-13 



0-20 



trace 



99-42 



Impure jet. Port 

 Durnford. Mus. No. 228. 



Including 



the 

 moisture. 



Excluding 



the 12-88 

 per cent, 

 moisture. 



r 



12-88 



43-95 



6-79 



30-18 



' 1-63 

 0-52 

 1-01 

 1-03 

 0-24 



015 



1-14 



99-52 



Per cent. 



50-48 

 7-80 



34-67 



1-87 

 0-60 

 116 

 1-18 

 0-28 



0-17 



1-31 



99-52 



