-2368 ARBORETUM AND FRUTICETUM, I'AUT 111. 



which, towards the end of May, and during the months of June and July, 

 exudes, according to some, during the night, from the bark of the young 

 shoots; but which, according to others, transpires from the buds and leaves, 

 on which it coagulates in the form of little white glutinous grains, which are 

 easily scraped off. In the morning, young larch trees, before they are struck 

 with the rays of the sun, will be found covered with it ; but the grains, if not 

 gathered, will soon disappear. Very cold winds prevent the formation of 

 this substance, which is called manne de JBriancon, because it is found in most 

 abundance in that country. It resembles the manna of the flowering ash 

 (O'rnus rotundifolia, see p. 1242.), but is less purgative. It is not much 

 used, as but very little is produced, except in Briancon ; and, even there, it 

 is very difficult to collect before it melts. 



The Leaves of the larch, Kasthoffer considers as less injurious to pasture 

 than those of any other pine or fir ; and, for the same reason, he says that 

 they are better worth collecting as a manure. They are eaten in Switzerland 

 by cattle and sheep, but less eagerly than those of the evergreen pines and 

 firs ; because they, being deciduous, are only to be found in an eatable, that 

 is green, state, when the more palatable food of grass is abundant. 



Uses of the Larch in Britain. Public attention was first drawn to the uses 

 of this tree, as we have already observed, by Dr. Anderson, in 1777, when 

 the oldest larch trees in Scotland could not have been above 50 years old, 

 and, doubtless, none of them had been cut down ; as the earliest notice of 

 one of the Athol larches having been felled is in that year. ( See App. to Gen. 

 Rep. of Scot., vol. iv. p. 493.) Dr. Anderson's sources of information, there- 

 fore, must have been foreign authors, the more important of whom have 

 been already quoted. The first British author who treats of the value of 

 the wood of the larch at length, and from his own experience, is Pontey ; 

 who, in his Forest Pruner, the first edition of which was published in 1805, 

 states that the larch excels foreign fir in all the following respects : 



"1. It is much clearer of knots, provided a very small degree of attention 

 be paid to it, during the first twenty years of its growth. 



" 2. It is more durable ; for though it produces dead knots, when neglected, 

 still it produces no rotten ones, or what carpenters call cork-knots. The 

 fact is, that not only the heart and sap of the wood, but even the bark, are 

 so durable a nature, that we know no means of estimating when any one of 

 them will decay, except under some species of mismanagement. There is a 

 particular criterion by which larch is distinguishable from any other wood, 

 which is, at the same time, a decisive proof of its durability ; viz. the dead 

 knots, or branches, wood and bark, being always found fast wedged, as it were, 

 in the timber; so that every knot of that description has a sort of ring round 

 it nearly black. Any person who has larches growing, of some tolerable age, 

 may convince himself of their durability, by examining their dead branches; 

 which, whether great or small, are never found rotten. 



" 3. Larch is much less liable to shrink than foreign deal. It is well 

 known that the latter is exceedingly liable to that defect, in the first instance ; 

 and the joiners tell us that, when a board of it has been twenty years in use, 

 if planed over again, it will again shrink : but not so with larch ; for, if well 

 dried at first, it never shrinks at all. 



" A piece of larch wood, split from the root end of a slab, was weighed at 

 different periods. The tree having been cut down in August preceding, 

 and sawn up a few days previous to the first weighing, gave the following 

 results : 



Date when weighed. lb. oz. Date when weighed. Ib. oz. 



"1799, 1st October - - 12 11 "1799, 9th December, - - 7 11 



19th October 10 4 30th December, .-79 



25th October - 90 1800, 31st January, 7 9 



13th November, - - 7 13 



" The weighing has often been repeated since, but no variation was found 

 while it was in the same place ; namely, a dry room over one where a good 

 fire was kept. The piece is nearly all sap wood. From which we gather 



