AND m A T COSTS IN CHEMICAL WORKS.
. 203 r a u i t s 80 far obtnincd wcro considered sufficiently suggcstivc t o wnrrnnt publicntion b thcniselvcs. Tho results of thcso vulcnnising tcsts wilf bo publislicd ns soon as nvniinblc.
S icncc, L q n result of microscopio osnniinntion of Pnrn rubfjcr, nttributcs tho suporior qunlitics of 1" 'inc Hnrtl Porn t o tlio prcsenco of tough protcin fibrcs. Ho docs not nccount for tlic ciiffcrcnccs i n the dcgrcu? of toughness of tho fibres of diffcrcnt rubbers. nor does 110 nttcmpt to corrclnto tlio cxietcnco of such fibrous nintcriul running through thc cnoutchouc with tho physical propertics of rubbcr. Tho writcr ha. not bcon nblo to detect tho prcscnco of fibrcs in rnw rubbcr. Obvcrvntion of tlic process of congulntion undcr tho microscop sliowcd tlint tho cnoutcliouo globulcs nro ctuhddccl in tlic protcin rntlicr thnn cicc rwm, n i d tlint on prcssing tho congiilum .imicntli tho corcrslip conlesccnco of tlic caoutchouc nnd protein tnkes plnco with fonnntioii of whnt nppcnrs to bo n solid solution of tho two constituents.
Tho pnrt plnyed by cnoiitchouc globulcs during congulntion nlso requires considcrution. Sirico thuy exist in tho lntcs in n stnto of Browninn movement wliicli is considcrnbly nffectcd by chnngcs in conccntrntion of snlt nnd acid, it iy vcry probnblo tlint their pliyaicnl proprties in tho find product nru ulso nffcctcd by thcrio chnngcs. Scliitlrowitz line shown thnt tho viscositios of rubber soliitiona in bonzcno vnry nccording t o tho unlit of tho rubber. I n Impnring such solutions, tho b n r lquid is decnntcd off from tho insolublo nitrogcnous constituent. It follows therefor0 thnt tho propcrtiw of tho protein in tlio rubbcr hnvo no infliioncc on tlie viscosity dctcrminntion nrid thnt tho condition of tliu cuoutcliouc itself vnrics nccording to tho method of prclmrntic.n of tlic siini~ilc. Furthcr, if tho quality of n snniplo of rubber is tlelrndcnt on tho pro~wrtic~ both of tho cnoutcliouc nntl of tho protcin, and theso proptic-niny vnry in diffcrcnt clircctions nt tho snmo timo. it is Imssiblo thnt n given snmplo of rubber rnny bo infcrior in pencrnl pliysicnl properties to anothcr snmplo after vulcnnisntion, but nulrrior to it in tho viscosity test. This is found to bo tho cnsc in nctoal prnctico, nnd ns a resiilt much doubt lins becn thrown on tho vuluo of viacosity tcuts.
Tho prol~lcm thnt rcrnnins to bo E O ~\ -C ~, thcrcfom. is d i n t conditions dctcrniino tho physicnl proporties of tlio cnoutcliouc in rubber. Tho writer icnres furt licr discussion of this question until tho nbovo-incntioncd vulcnnkntion tcsts nro nmilnblc.
Bcforc concluding I wish to u s )rcss m y indcbtcdncss t o 3Ir. Shnrples, A.H.C.Sc., of tho kycologicnl Depnrtrncnt. Fed. Malay States, who cont1uck.d espcrimciits in con. junction with thcso on tho offcct of vnrying snlt conccntrntions on tho growth of orgnnisiiis cnuaing tlio s iotting of plnntntion rubber. rcsiilts of aliicli will nppcnr olacwlicro : also to Mr. Lnnibournr. F.R.H.S., Snprintcndcnt of Govcrnnlerit l'lnntntions, for nssistnnco in ninny other ways.