1902. 



FORESTRY AND IRRIGATION. 



343 



Elemi. A. Tschirch and J. Cremer 

 (Arch. d. Pharm., 240, 293). The 

 elemis may be classified in two groups 

 one which on mixing with alcohol shows 

 crystalline constituents, and one which 

 under these conditions remains amor- 

 phous. All elemis are derived from 

 Burseraceae. The Manila elemi is ob- 

 tained from Canarium, the Brazilian 

 from Protium, the Yucatan from Amy- 

 ris, the former East African from Bos- 

 wellia, and the present East African 

 probabh- from Canarium. The authors 

 have studied a Canarium, a Protium, 

 and an Amyris elemi. 



1. Manila elemi, soft, almost white, 

 soluble in ether, chloroform, etc. acid 

 number, 20-22 ; saponification number, 

 29.5-33.5. It was found to contain: 

 (a) -manelemic acid, C.j-H-0^, cr3'stals, 

 M. P.^2i5 C. acid number, 102-106 ; 

 saponification number, 190-204 ; (d) 

 j5-manelemic acid, C4^H,,^|0^, amorphous, 

 inactive, M. P.=75-76 C. acid num- 

 ber, 90-96 ; saponification number, 112- 

 118 ; (r) - and ,?- am^'rin whose prop- 

 erties have been described by Vester- 

 berg ; (d) bryoidin, C.jH^.Og, i per 

 cent, M. P. 135. 5 C, inactive; (e) a 

 bitter principle, 1-2 per cent ; (/) an 

 ethereal oil, 20-25 P^r cent, B. P. 

 chiefly i7o-i75 C, 0=0.955; Ct) 

 maneleresene, C|-H,^0, 30-35 per cent, 

 white amorphous powder, M. P. 63- 

 65 C. This elemi was obtained from 

 Canarium commune, L. 



2. Yucatan elemi. Obtained, accord- 

 ing to Henkel, from Amyris elemi f era 

 Royle ; contains no resin acids. The 

 following constituents were separated : 

 () Yucamyrin, 10-15 per cent, which 

 was separated into - and [j- amyrin, 

 M. P. 179 C; {K) yuceleresene, C,,^ 

 H,,0, 60-70 per cent, M. P. = 75-77 

 C; (r) ethereal oil, 8-10 per cent, 13= 

 0.945 ; (^) a bitter principle. 



African elemi ( Kamerun elemi ) . Re- 

 cently introduced, probably obtained 

 from Canarium scii'veinfiirthii Engl. 

 Constituents : {n) afelemic acid, 8-10 

 per cent, C^^H^^O^, white amorphous, 

 M. P. = g7-98 C, soluble in usual 

 solvents acid number, 81-90; saponi- 

 fication number, 100-104 ; ^b^ afamy- 

 rin, 20-25 per cent, C^nHjoO, needles, 

 M. P. = 170 C. ; (r) ethereal oil, 15-20 



per cent, 0=0.953, B. P. chiefly i6o- 

 175 C. ; {d') afeleresene, 40-45 per cent, 

 C,H,,0,, M. P. = 7o-73 C. 



Analysis of Tanning Materials : Filter 

 Papers and Soluble Solids. H. C. Reed 

 (Journ. Soc. Chem. Ind., 21, 691. S. 

 and S. filter papers No. 590 give the 

 most satisfactory results. The filter 

 must be kept full during filtration, and 

 clear filtrates are always obtained when 

 2 grams of kaolin are used as an assist- 

 ant. The author recommends the gen- 

 eral adoption of the official method used 

 in the United States and the exclusive 

 use of S. and S. filter paper No. 590. 



The Solubility of some Soft Resins. 

 Ch. Coffignier (Bull. Soc. Chim., Paris 

 (3)' 27, 549). The literature contains 

 many contradictory statements on this 

 subject. The question is of considera- 

 ble importance in the manufacture of 

 varnishes, and the author has deter- 

 mined the solubility of dammar, sand- 

 arac, and mastic. 



Robinin, Violaquercitrin, Myrticolo- 

 rin, and Osyritrin. A. G. Perkin 

 (Journ. Lond. Chem. Soc, 81, 473). 

 Robinin is prepared by extracting the 

 flowers of Robinia pseiidacacia with hot 

 alcohol, concentrating the extract, and 

 pouring it into water. The residual 

 alcohol is removed by distillation and 

 the resulting aqueous solution is ex- 

 tracted with ether. Robinin has the 

 formula C,,,H^.,0,,o or C.H4tO.!n- It is 

 hydrolized by acids, the products being 

 campherol, small quantities of dextrose, 

 and rhamnose (not galactose, as pre- 

 viously stated). The dextrose may be 

 due to the presence of traces of another 

 glucoside. The hydrolysis of the robi- 

 nin is therefore represented by one or 

 the other of the following reactions : 



C,,H0,o+4H,0=C,,H,A+3CH,A; 



C,,H,,0,o+4H,0-C,,H,A + 2CeH,A+ 

 C.H,0. 



Investigations on Brasilin. St. v. 

 Kostanecki and V. Lampe ( Ber.deutsch. 

 chem. Ges., 35. .667); and E. Bollina, 

 St. V. Kostanecki and J. Tambor (Ber. 

 deutsch. chem. Ges., 35, 1675. ) 



The Nature of Caoutchouc. C. O. 

 Weber ('Ber. deutsch. chem. Ges., 35^ 



1947)- 

 Earch Turpentine and \^enetian Tur- 



