93 
Sorby, the secretary of the Literary and Philosophical 
Society of Sheffield. The analysis was made chiefly with 
a view to ascertain the relative amount of animal matter 
contained in the three principal varieties of ivory, and the 
result was as follows : — In African ivory the proportion of 
animal to earthy matter was as 101.100, in the Indian as 
76.100, and in the Egyptian as 70,100, the earthy matter 
being in all of them principally phosphate of lime. 
Thus, though the composition, on the whole, is much 
the same, yet there is a sufficiently well marked difference 
in the ratios of the animal and earthy matter they respec- 
tively contain. The large amount of animal matter con- 
tained in the African ivory, taken in connexion with its 
greater density and its greater power of retaining water, 
may account for the semi-diaphanous appearance which it 
presents, and which forms so great a contrast with the 
Indian or Egyptian ivory. 
Ivory dust is a substance which has long been used for 
making jelly, but, from the analysis I have just read, it 
appears that the strength of the jelly would depend on 
the ivory from whence the dust came. Equal weights of 
dust from African and Indian ivory were boiled for six 
hours in water, which was then freed from dust, and evapo- 
rated to dryness; the dust from the African ivory yielded 
seven per cent of hard gelatine ; the dust from the Indian 
yielded nearly four per cent, of the same substance ; so that 
to make a given quantity of jelly, double the quantity of dust 
would be required from Indian than from African ivory. 
From the experiments and observations set forth in the 
foregoing remarks, it appears certain that when articles in 
ivory, whether intended for utility or ornament, are desired 
to retain their beauty for the longest period possible, it is 
advisable to have them made from African ivory, as it not 
