305 





Raphionacme utilis. — In the Kew Bulletin^ No. 5, 1008, pp. 209- 



215, an account was given of the new Ecanda rubber plant from 

 Portuguese West Africa. Mr. John T. Norman, of the City 

 Central Laboratory, 23, Leadenhall Street, E.C., who had also 



some 



some of the " mutares " (native rubber prepared from the roots) 

 for investigation, has kindly forwarded the following report to 

 Kew : — 



?/ 



)f the tuberous roots of Raph 



" The roots were covered with a dry, brown, parchment-like 

 skin, and in some cases were much shrunken and decomposed. 

 On cutting the fresher roots, a white latex of pleasant odour freely 

 exuded, whilst on tearing apart those which had decomposed, 

 threads of a substance resembling caoutchouc were observed. 



"The * mutares' were grey irregular lumps, roughly finger- 

 shaped ; they possessed an earthy and somewhat musty odour, 

 but although obviously contaminated with soil and fibrous matter, 

 they exhibited considerable resiliency. 



" Analysis of the Mutares. 



" Caoutchouc 



Resin, &c, by alcoholic extraction 

 Moisture or matters volatile at 100° C. 



• • 



• • • 



Mineral matters 



Fibre and matters soluble in water 



• • 



* • 



80-4 

 64 

 1-6 

 4-4 



72 



100-0 



" The caoutchouc was obtained from the residue after extraction 

 by absolute alcohol and water ; it was dissolved in toluene, the 

 solution filtered and the filtrate precipitated by alcohol. Since 

 this method proved troublesome when working quantitatively, 

 owing to the swelling of the mass and the great difficulty of 

 removing the last trace of solvent, the estimation of the caout- 

 chouc was eventually effected by dissolving the ' mutares rubber 

 in carbon tetrachloride, and then forming the tetrabromide, 

 which is a white powder equivalent to 0'298 of its weight ot 



caoutchouc. 



" Analysis of the tuberous roots. 



Caoutchouc ... ••• !j.q! 



Resin, &c, by alcoholic extraction ... ••• *■'** 



Dried extracted residue orvifi 



Water and water soluble substances... — w ' ib 



10000 



« In this analysis the root was dried at 100« C., and thtn 

 extracted with absolute alcohol, water, carbon tetrachlonde, ana 

 the extract finally treated with acetone to precipitate the caoui 



chouc. 



