176 THE GUANO AND OTHER PHOSPHATIC DEPOSITS 
The Guano and soa Phosphatic Deposits occurring 
n Malden Island. 
~ W. A. Drxon, F:C.S. 
[Read before the Royal Society of N.S.W., 3 October, 1877.] 
Tue guano deposits on Malden Island are entively pecans 
and occur either on the spot where deposited by the birds, or 
crevices and pockets amongst the rocks, where it seems to have hail 
washed by water or blown by the wind, or possibly it may have _ 
extensive, but Moi fot in value—much of it being too poor to 
ar the cost of removal. 
Having left the “faland rather hurriedly, owing toa severe illnes 
I unfortunately lost a note-book containing analyses of the different 
deposits, phosphatic minerals, plant-ashes, &c., and have therefore 
, to fall back on some analyses in a rough note-book, made by an 
expeditious method, for the purpose of ascertaining what deposits 
were worth working. After ignition to expel organic matter 
water, the process used was, to dissolve the ash in a minimum of 
hydrochloric acid, precipitate tricalcic phosphate by amm onia, 
dissolve the washed precipitate, and after addition of a small 
quantity of tartaric acid, re-precipitate with ammonia and weigh as 
tricalcic 2 egg = eggaalees: ash being tested to ensure the absence of 
carbona This process, though not absolutely ‘accurate, 
these deposits, and the last two together never amounted to more 
than 0°25 per cent. 
The following analyses show the general composition of the 
recent guanos ase method :— 
ecent ctr hoe? 
_ Water and bur matter 10 14:10 
a phosphate... sips ee bs 72-49 » 7921 
ae te me si aes ae 4:19 
y ” sulphate 5°82 21i 
ingcue um carbonate, alkalies, sand, andloss 1°96 33 
‘ 10000 pestis 
__® See H. Pellet, Bull. Soc. Chim. [2] xvu, 105; and Chem. Soc. Jour. 
[2] xvi, 578. 
+ See also Fettbogen, Chem, Soc., Jour. [2] x, 1,112; and-“Voelker, Jour. 
ameehae feo 2, [2] xa, 440, 
