The chemical composition of carbohydrates of wood cells

Wood cell fractions were quantitatively prepared from pine wood and holocellulose, from spruce holocellulose, and from birch holocellulose. The vertical tracheids were separated from ray cells of pine wood by micromanipulation under a microscope. The total hydrolysate of the tracheids contains more mannose and less xylose than the hydrolysate of the ray cells. The vertical tracheids and ray cells were fractionated from pine holocellulose by being first passed through a 40 mesh laboratory screen and then through a 180 mesh screen. The tracheids amounted to 97.8% and the ray cells 1.8% by weight of the holocellulose. The total hydrolysate of the tracheids was found to be richer in mannose and poorer in xylose than the hydrolysate of the ray cells. Both cell fractions were found to contain nearly equal amounts, about 20%, of hemicellulose soluble in an alkaline borate solution (17.5% NaOH + 4% H3BO3). Mannose was the predominant (nearly 70% of neutral monosaccharides) monosaccharide in the hydrolysate of the hemicellulose of the tracheids; xylose (nearly 50%), in the hydrolysate of the hemicellulose of the ray cells. The latter contained more glucose, arabinose, and galactose than the tracheids. The spruce holocellulose was found to contain 98.9% vertical tracheids and 1.1% ray cells by weight in microscopical fractionation. The total hydrolysate of the tracheids prepared via screening of holocellulose was found to be richer in mannose and glucose and poorer in xylose and arabinose than the hydrolysate of the ray cells. The hemicellulose amounted to 17.8% of the tracheids and to 30.3y0 of the ray cells. The total hydrolysate of the hemicellulose of the tracheids was found to be richer in mannose and poorer in xylose, arabinose, and galactose than the hydrolysate of the hemicellulose of the ray cells. Mannose was the predominant (50% of neutral monosaccharides) monosaccharide in the hydrolysate of the hemicellulose of the tracheids and xylose (50%) in the hydrolysate of the hemicellulose of the ray cells. The prosenchyma and parenchyma cells were fractionated from birch holo‐cellulose by scretmirig. The vessels have been separated from the fibers by manual fractionation of the prosenchyma cell fraction under a microscope. The holocellulose was found to contain 86.1% fibers, 9.3% vessels and 4.6% parenchyma cells, by weight. The ratio of xylose/glucose in the total hydrolysates of the fibers and of the vessels was about 0.6: 1.0, but xylose was the predominant (77% of neutral monosaccharides) mono‐saccharide in the total hydrolysate of the parenchyma cells. The hemicellulose was 21.5% of the prosenchyma cells and 39% of the parenchyma cells. The hydrolysate of the hemicellulose of the prosenchyma cells was found to be richer in mannose and poorer in xglose than the hydrolysate of the hemicellulose of the parenchyma cells. The former was found to contain xylose 86% of neutral monosaccharide; the latter 93%.