1,c:ctiire given 011 tlie occiision of the visit of the 1,ondon Section and t Iic Pliistics Gronp of tlic society to the Ri11~l)er I<shit)itioii on iipri] 12, 193.5.
Tlic Iliilibcr 1Csliil)itioii 110s l~ecii orgiinizetl to bC as co~nprclicnsivc :is possililc iincl to 11i1vc tlic witlcst pt~ssiiblc iippcnl not only to the tccliniciil n i i i n but iilso to t lie gciiernl pi~ldic. Xcrcrtliclcss, such i i n cshilitinn will be vie\vcd by tliffcrcnt types of intlividiiiils f'roiii clifl'crcnt tingles ;in11 it is the piirposc o f this short talk to attcnipt, to bring oiit its sl)rci:il :ippciil to tlic tcchniciil clicinist, prticiiliirly tlic chcniist who specializes in plast irs ot I i t ~ t,hnn
It is ini~wrtiint first of 1111 to obtiiin sonie itlcii of t lie historiciil I~:ickgroiinti to t,he r i i l i l i c ~ industry. 1 ~1 1 I ~l ~c r liiis p~1)iiI~ly 1)ecn iisctl froin t lie cii rlicst tiincs in tlic districts i n wliicli the ~v i l t l riiI)lwr trcc floiirislictl, Illit it w m first introtliiccd into Ihropc! by Christoplicr C'olunibiis on his rctiirn from his sc~contl voyiigi:, tlioiigli it wiis not until tlic 19th cc!iitiiry t l i i i t iniliortiint teclinicril progress wiis mnclc which rrsiiltctl in n riil~bcr tccliniqiic which is biisiciilly t I i v tc.cliniqiir cniployctl in rii11l~c.r niiiniifiict lire n t t,hc prcsrnt time. liiincock in 1820 tliscovcrcd t,lic lmiiking down or niiistication of riibbcr by working riil)bcr IJc.twcwi rotiit ing cylintlcrs. A few yciirs nftcr this Cliiirlt*s Miiciiitosli niiidc tlic ol~PC!r'iit ion tlint riitiijer coiiltl be tlissol~ctl in coal tar n:ipIitIiii ii1111 tliiis Iiiitl tliu foiiutliition of tlic ~~)rciitlirig intliistry.
Xiit 1i:inic.l IIiiywiriI in 3530 tlisc.ovcrctl surface viilciiniziition by cxposiirc to siinliglit~, i i n t l Coodyciir cliscovcwcl dry 1ic:it vulcaniziition by cxpsing :I