1813.] ffoin Botany Bay. \ 165 



fracture is vitreous, and the colour Dot unlike: that of sliell lack. 

 It is verv battle, cramblingto powder between the fingers. The 

 loss iiu. .dined amounted to 0*45 of the original weight. On 

 exposing the plate of glass on a furnace to a heat of about 212°, 

 the gum sustained an additional loss of O'll of the original 

 weight; making the whole loss to amount to '56. 



To learn what had occasioned the loss of weighty 100 grains 

 of the liquid gum were pot into a small glass matrass, fitted with 

 a capital and receiver, and exposed to a heat not much exceeding 

 212^. When the distillation was finished, the dry residue in 

 the matrass weighed 43*5 grains. It resembled in every respect 

 the solid matter left when the liquid gum is exposed to the open 

 air. The receiver contained a quantity of water, weighing 53*5 

 grains. Thus there was a loss incurred amounting to 3 grains. 

 I ascribe this loss to the escape of moisture- for the receiver was 

 not luted. 



The water thus obtained was limpid and colourless. It had 

 the peculiar smell of the gum, and a slight taste not easily 

 described. It did not alter the colour of vegetable blues, nor 

 exhibit any thing remarkable, when treated with the different 

 re-agents. The dry residue smelled like bees'- wax, or at least 

 that smell was diffused through the matrass. This dry residue 

 continues always solid and brittle, and is not affected by any 

 degree of heat not sufficient to produce decomposition. 



Thus it appears that our liquid gum is a compound of 44 parts 

 of solid matter and 56* parts of water, and that it is indebted to 

 the water for the property of becoming liquid when heated. 



To the 43*5 grains of solid residue in the matrass, 56*5 grains 

 of distilled water were added, to make up the original weight. 

 By long-continued digestion in a heat scarcely exceeding 100^^ 

 the water gradually incorporated with the dry matter, and formed 

 with it a compound agreeing in every respect with the original 

 liquid gum. By distillation this water was driven off': it had the 

 smell of the liquid gum as before, while the dry residue had the 

 odour of bees'-wax. 



Here, then, we have a compound to which chemists have not 

 hitherto paid attention, a combination of water and dry vegetable 

 matter, nearly solid while cold; but becoming liquid by heat,^ 

 like resin or was. 



Though tins liquid gum contains so great a proportion of 

 water, it exhibits no strong disposition to combine with any 

 more. When put into water it immediately tinges that liquid 

 of a muddy red, but a portion falls to the bottom ; nor was I 

 able to procure a complete solution of it in cold water. Hot 

 water acts better ; bjut a portiou precipitates again as the solution 

 cools. 



