Good Deal

'Deal' is a more or less obsolete word meaning 'trade softwood'. It might be pine, spruce, or fir. These pics. are of a pine species bought at my local timber suppliers. The timber came from Russia. It was of superb quality, very dense (for pine) and even textured, with up to two growth rings per millimeter. This meant that my 6" plank came from a tree at least 200 years old. They grow slowly in those latitudes.

These are unstained thin sections, cut with an ordinary (extra sharpened) plane iron. They are mounted in Canada balsam, another tree resin, much used in microscopy. The colour is introduced by an optical technique called Rheinberg illumination which uses coloured glass or plastic filters in the substage condenser. It is useful for picking out structures, lying at right angles to one another, in contrasting colours. Thus the long grain in the top pic. shows up in yellows and blue while the medullary rays show in red.

In the bottom pic., the cross section, the black patches or holes are resin canals which run longitudinally, along with the main grain. Six rings are showing representing six years growth. It is interesting (to me) how the resin canals are disposed. Ring 1, left, two canals in the autumn. Ring 2, nothing; ring 3, nothing, ring 4 two canals in winter wood, ring 5 nothing, ring  6, right hand, one in spring and three in autumn. Is something controlling their formation, or is it just random? Are  they laid down with the growth rings or do they appear later? They don't appear to have much structure as such, unless my primitive methods have destroyed it, they are just holes. If you know the answer (or if you don't) please comment.