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THE POPULAR SCIENCE MONTHLY. 



process invented by Jo-rdery and Pasehkoft" 

 for the solidification of petroleum, thus 

 making it more easily and more safely trans- 

 portable : " First make a decoction of the 

 root or leaves of the Saponaria officinaria, 

 quillay, or any other substance possessed 

 of saponific properties. Then an amount 

 of this decoction or extract, equal to one- 

 twentieth of the petroleum to be solidified, 

 is placed in a vat, and the petroleum suf- 

 fered to flow in upon it slowly, the whole 

 being constantly stirred in the mean time. 

 This process may be followed with oils in 

 general, and with volatile oils it will prevent 

 loss from leakage and obviate many of the 

 dangers now attending their transportation." 



Cnrioas Phenomenon in Vegetable Phys- 

 iology. It has long been known to botanists 

 that, occasionally, after the felling of pine 

 and fir trees, their stumps would continue 

 to increase in diameter, i. e., form new 

 woody layers for several years. Dutrochet 

 mentions some cases of extraordinary lon- 

 gevity in the stock of Pinus picea after the 

 trunk had been felled. He says that, in the 

 year 1836, a stock of Pinus picea, felled in 

 1821, was still alive, and had formed 14 thin 

 new layers of wood that is, one each year; 

 and another, felled in 1743, was still in full 

 vegetation, having formed 92 thin layers of 

 wood, or one each year. This singular 

 phenomenon was long a puzzle to botanists 

 and vegetable physiologists. Over thirty 

 years ago Goeppert, an accomplished bota- 

 nist of Breslau, undertook an investigation 

 of the subject. The result is published at 

 large in the " Annales des Sciences Natu- 

 relles " for 1843. It appears that in all the 

 cases examined by Goeppert there was a 

 union of the roots of the fallen trees with 

 the roots of living trees growing in the im- 

 mediate vicinity, and his explanation of the 

 phenomenon was that the stumps maintained 

 their growth by drawing their supplies of 

 eap from the trees with which they were 

 thus connected. The union of roots in 

 these cases was sometimes woody, and some- 

 times only by the bark of the roots. So far 

 as observed, this anastomosis, or natural 

 grafting, is confined to coniferous trees, 

 and to only a few species of them, chiefly 

 the silver-fir, the spruce, and occasionally 

 the Scotch fir. In the London Gardeners' 



Chronicle of August 31st is an account of 

 an instance of this kind of anastomosis of 

 the roots of a larch, and a figure is given 

 of the specimen, in which the stump and its 

 root -connections are exhibited. The cut 

 stump shows rotten wood in the centre, with 

 the new wood at the circumference surging 

 over the edges of the wound. 



Although the discovery of this root- 

 union explains some of the questions in- 

 volved in this curious phenomenon, it does 

 not explain them all ; for instance, why does 

 not the sap, which is thus robbed from the 

 roots of the nurse-tree, pass up in the 

 usual channels and overflow at the top of 

 the stump, as is the case when a grape-vine 

 or deciduous tree is cut during the active 

 ascent of the sap ? As the growth of new 

 wood in exogenous trees takes place from 

 the cambium, and the cambium is supposed 

 to be the sap which has been elaborated in 

 the leaves, what is the source of the cam- 

 bium in these stumps ? 



It would seem as if there was here a 

 complete contradiction of the ingenious 

 theory of some of the French botanists that 

 wood growth begins in the leaves or leaf- 

 buds, and descends continuously thence to 

 the roots, so that, in fact, wood may be con- 

 sidered the united mass of roots which 

 emanate from the leaves of the plant. 



The theory of De Candolle is, that the 

 woody and cortical layers originate laterally 

 in the cambium furnished by preexisting 

 layers, and nourished by the descending sap. 

 To use the words of De Candolle, " The 

 whole question may be reduced to this : 

 either there descend from the top of a tree 

 the rudiments of fibres which are nourished 

 and developed by the juices springing later- 

 ally from the body of the wood and bark, 

 or new layers are developed by preexisting 

 layers which are nourished by the descend- 

 ing juices formed in the leaves." The lat- 

 ter part of this statement, though somewhat 

 vague and unsatisfactory, probably involves 

 the true theory of the formation of wood. 

 The preexisting layers mentioned in De Can- 

 dolle's statement include the medullary rays 

 which reach the circumference. These me- 

 dullary rays are composed of cellular tissue 

 derived from the pith, and, like it, are ca- 

 pable of indefinite extension by cell-multi- 

 plication. 



