[8] We are not in possession of sufficient facts to judge of the effect to hasten or deter decay occasioned by the timber having been softened in hot liquids of 212° or upwards, and not raised so high as to generate pyrolignous acid; but we think it must impair the elasticity. [9] As excellent plank can be obtained by importation, the grower of naval timber ought to regard the production of crooks as a more patriotic occupation than the production of plank. _It will generally pay better._ {31} PART II. BRITISH FOREST TREES USED AS NAVAL TIMBER. OAK—_Quercus_. Oak appears to be the most prevalent tree about the middle of the north temperate zone, growing, naturally, upon almost every soil, excepting some of the sterile sandy hats. With the exception of the pines, it is by far the most useful kind of tree, almost balancing the accommodating figure of stem, and manageable quality of the pine timber, by its greater strength and durability, and excelling the pines in value of bark. It is not easy to determine whether there be distinct British species in the genus _Quercus_; but, at least, there are several breeds, or families, or grouped resemblances, which, though the individuals may slightly vary, and though a gradation, or connection, may be traced among these families themselves, yet possess general character sufficiently marked to support names. Botanists, who are so prompt and so well prepared with their classes, {32} orders, genera, species, varieties, long before they acquire much knowledge of what they are so ready to classify, or be able to distinguish between species and variety, or know if species and variety be really distinct, divide the oak of this country into two species, _Quercus Robur_ and _Q. sessiliflora_, the former with long fruit-stalks, and hard, strong, durable timber, the late leafing old kind once so prevalent in the island: the latter an earlier leafing, faster growing kind, timber inferior, leaves petiolate, fruit sessile, not common, but supposed native. We consider there is no foundation for this specific distinction; we have met with oaks with various lengths of fruit-stalks: Besides, short and long fruit-stalks is a very common difference among seedling varieties. The families or breeds which we have observed in the indigenous oak resemble what are found among almost every kind of vegetable, and graduate into each other,—those farthest removed in appearance, no doubt having power to commix by the pollen. The most remarkable distinction we have observed is in the colour of the bark, whether inclining to white or black. The variety or breed with grey white bark, often very smooth and shining, and sometimes beautifully clouded with green, has also a different form of leaf and figure of top from those with {33} blackish bark, and we have no doubt will also afford a different quality of timber. Those with blackish dingy bark vary considerably from each other, some being