SECRETIONS OF CONIFEROUS PLANTS. 29 



deprived of its volatile part. The Eesin left in the still after the 

 separation of the essential oil differs in appearance and properties 

 according to the amount of impurities contained in it. The best 

 Eesin is brownish yellow, crystahses in small rhombic prisms, is 

 insoluble in water but is dissolved by alcohol; it is a non-con- 

 ductor of electricity, and in its fossil state is known as amber. 



The resinous products of Coniferous trees are enumerated by Dr. 

 Lindley* as follows : — " Common and Burgundy Pitch are obtained 

 from Pinus sylvestris; Hungarian Balsam from P. montana; a most 

 fragrant resin from Araucaria brasiliends; a hard brittle resin like 

 copal from Dammara australis; Bordeaux turpentine from Pinus pinaster; 

 Carpathian balsam from P. pineal Strasburg turpentine from Abies 

 pedinata ; Canadian balsam from A. balsamea. The common Larch 

 yields Venetian turpentine, and a saccharine matter called Manna of 

 Briancon exudes from the branches. Liquid storax is thought to be 

 yielded by the Dammar Pine.t Sandarach, a whitish-yellow, brittle, 

 inflammable, resinous substance with an acrid aromatic taste, is said by 

 Brongniart to be the tears of Callitris quadrivalvis. The substance 

 from which Spruce beer is made is an extract from the branches of 

 Abies canadensis and of A. ni(]ra. Great tanning powers exist in the 

 bark of the Larch. The stimulating diuretic powers of Janiperus 

 Sabina are well known, and are partaken of in some degree by the 

 common Juniper, the diuretic berries of which are an ingredient in 

 flavouring gin; the fetid oil of Juniperus oxycedrus is employed in 

 veterinary practice." From the descending sap of the Larch and other 

 trees of the Pine and Fir tribe is obtained the substance called Coniferine, 

 which, by a comparatively recent discovery, can be transformed into 

 Vanilline, the aromatic principles present in the seed vessels of Vanilla. 

 The collecting of Coniferine has quite lately become a profitable branch 

 of industry in North Germany. 



The amount of the secretions yielded by Coniferoiis trees appears 

 to be influenced by the heat or moisture of the climate ; the former 

 acting as a stimulant, and the latter as a check to their production. 

 The Pine forests in the Mediterranean region and the plantations in 

 the south of France supply turpentine in greater quantity and of 

 better quality than that obtained further north, while the Pine Forests 

 of Sweden and Norway supply only the coarser products as tar and 

 pitch. The turpentine of American commerce is procured chiefly from 

 the extensive " Pine Barrens " of the South Eastern States, where, 

 during the great heats of summer, it flows from the trees so copiously 

 as to require but a comparatively small amount of labour to obtain 

 it. In the great pine woods of Canada, it would not at present 



* The Vegetable Kingdom, p. 229. t Dammara orientalis. 



