TRANSACTIONS OF THE SECTIONS. 39 



Accordingly the composition of this specimen of Mack shale may be repre- 

 sented as follows: — 



Tribasic phosphate of lime 5215 



Lime present as fluoride of calcium and as silicate 4-23 



Magnesia '32 



Alumina 7 - 71 



Oxide of iron 2-01 



Sulphuric acid -26 



Iron pyrites 7-52 



Insoluble siliceous matter 2244 



Organic matter and loss 336 



100-00 



On the Composition of a Marine-Boiler Incrustation. 

 By Dr. Aug. Voblcker. 



A marine-boiler incrustation, analyzed by Dr. Voelcker, jdelded the following 

 results : — 



Moisture 101 



Water of combination 7 - 48 



Oxides of iron and alumina, with traces of phosphoric acid . . -64 



Lime 3005 



Magnesia 16*72 



Sulphuric acid 42-60 



Chlorine -90 



Soluble silica -06 



Fluorine , traces. 



Alkalies. and loss - 54 



100-00 



This incrustation did not contain a trace of carbonate of lime or magnesia, two 



constituents always present in ordinary boiler incrustations. 



Supposing the chlorine found to be present as chloride of sodium, and uniting 



sulphuric acid with lime, we obtain the following results : — 



Moisture (left at 212°) 1-01 



Water of combination 7-48 



Oxides of iron and alumina, and traces of phosphoric acid .... -64 



Sulphite of lime 72-42 



Lime (probably present as fluoride) - 25 



Magnesia 16"72 



Chloride of sodium l - 48 



Soluble silica - 06 



100-00 

 The water of combination found in this analysis is just sufficient to form, with 

 the magnesia, hydrated oxide of magnesia ; for 16-72 of magnesia require 7'52 of 

 water, which agrees closely with 7 - 48, the amount found in the analysis. 



It thus appears that this incrustation consists mainly of anhydrous sulphate of 

 lime and magnesia-hydrate. 



On the Possibility of Manufacturing Neroli in the British Colonies. 

 By Dr. J. E. De Vbij. 



After his arrival in Java the author found there existed in Bandoug many 

 thousand shaddock trees {Citrus decumaiui). 



In higher localities like that of Bandoug, where the average temperature is much 

 lower than in Batavia, the fruit of the shaddock has only the size of an ordinary 

 orange, and is not eatable. As the many thousand shaddock trees growing in the 



