ELASTIC GUM VINE. 



'59 



pears upon the furface of the gum fo foon as the latter 

 has attained its folid form. The prefence of this 

 confiderably impeded the progrefs of my experiments, 

 as will be feen hereafter. 



I was at fome trouble in endeavouring to form an 

 extract of this milk fo as to approach to the confif- 

 tence of new butter, by which I hoped to retard its 

 fermentative ftage, without depriving it of its ufefui 

 qualities; but as I had no apparatus for diftilling, the 

 furface of the milk, that was expofed to the air, in- 

 ftantly formed into a folid coat, by which the evapo- 

 ration was in a great degree prevented. I, however, 

 learned, by collecting the thickened milk from the 

 infide of the coats, and depoliting it in a jelly pot, 

 that, if excluded from the air, it might be preserved 

 in this (late for a confiderable length of time. 



I have kept it in bottles, without any preparation, 

 tolerably good, upwards of one year; for, notwith- 

 ftanding the fermentation foon takes place, the de- 

 composition in confequence is only partial, and what 

 remains fluid, (till retains its original properties, al- 

 though confiderably diminifhed. 



Not having feen M. Fourcrofs memoir on Caout- 

 chouc, I could not make trials of the methods pro- 

 pofed by him for preferving the milk unaltered. 



In making boots, gloves, and bottles, of the elaftic 

 gum, I found the following method the bed: I flrft 

 made moulds of wax, as nearly of the (Ize and fhape 

 of what they reprefented as poflible; thefe I hung fe- 

 parately upon pins, about a foot from the ground, by 

 pieces of cord wrought into the wax : I then placed 

 under each a foup plate, into which I poured as much 

 of the milk as I thought would be fufficient for one 

 coat. Having dipped my fingers in this, I com- 

 4 pletely 



