THE INDIA-RUBBER INDUSTRIES. 



807 



of unvulcanized India-rubber. Here is a strip of India-rubber ; you 

 see that it is quite soft and pliable. I will now expose it for a few 

 minutes to a temperature of Centigrade, or the freezing-point of 



Fig. 2. The Operation of drying the India-rubber Juice. 



water. It becomes, as you see, rigid and stiff, but its original pliability 

 may be restored, either by warming, or by applying sufficient tensile 

 strain to it, to extend it to three or four times its length. One half 



