lS6 LATICIFEROUS TUBES. 



ground for deciding upon the possible chemical changes which result from drying 

 in the air. Reference must be made to the technical, and especially the pharma- 

 cological literature, for information on the above-mentioned investigations ^ Here 

 only some few results may be given of analyses of fresh specimens of latex, or of such 

 as were kept so as to prevent drying up, by way of giving a rough idea. 



Faraday '^ investigated the latex of a rubber-tree of the family Euphorbiaceae— ' Hevea 

 elastica, Siphonia elastica, Pers.,' probably H. guy anensis— which had been sent to 

 England in closed bottles. The fluid contained in looo parts- 

 Water with an organic acid 5^3 



Caoutchouc 3i7 



Albumen i9 



Bitter substance (with much nitrogen) and some wax . . 71-3 

 Bodies insoluble in alcohol, soluble in water .... 29-1 



The preserved latex of Galactodendron utile contains, according to Heintz*, in 

 100 parts — 



Water 

 Albumen . 

 WaxCCs^HcsOj) 

 Resin (C 36 H 58 O,) 

 Gum and Sugar 

 Ash . 



57-3 

 0.4 



5-8 



314 



4-7 



0-4 



Weiss and Wiesner * investigated the fresh latex of some indigenous Euphorbias. In the 

 slightly acid latex of E. Cyparissias they found in 100 parts — 



Water 7z-i3 



Resin 15-72 



Gum 3-^4 



Sugar and extractives , . . . 4-13 



Albumen 0-14 



Ash 0-98 



For comparison with these may be given the composition, as found by Fltickiger', of 

 Euphorbium, i. e. the fixed residue of the latex of E. resinifera — 



Amorphous resin (G 20 H32O J . . . 38 



Euphorbon (CjgHji O2) . , . . 22 



Mucilage' 18 



Malates, especially of calcium and sodium ^ 12 



Other constituents of ash , . . 10 



Sect. 46. The tubes themselves, in which the latex is contained, are all alike in 

 certain points of structure and arrangement, but may be divided, according to form 

 and development, into two categories, articulated and non-articulated laticiferous tubes. 

 Each of these categories is peculiar to definite families, the articulated tubes being 



' Compare Wiesner, Rohstoffe des Pflanzenreichs ; Fliickiger, Pharmacognosie ; Fliickiger and 

 Hanbnty, Pharmacographia ; Rochleder, Phytochemie, &c. ; also Meyen, Physiol. II. /. c. 

 " Compare Berzelius, Jahresbericht for 1827 (German by WoUer), p. 246. 

 ' Poggendorff's Ann. 65 (1845), p. 240. * Botan. Zeitg. I.e. 



° According to Fliickiger and Hanbury, Pharmacographia, p. 504. 

 " Probably inclusive of starch or its products of decomposition. 

 ' Compare the former statement for E. Lathyris. 



