Page:Popular Science Monthly Volume 29.djvu/629

Rh spheres in the resin-ducts and wood-cells I found in some white-pine lumber from Michigan, used for sheathing freight-cars. The wood was discolored and the medullary rays were mostly destroyed, especially those containing resin-ducts, which were penetrated from the exterior, the hypha spreading to the longitudinal resin-ducts and wood-cells; upon drying, the decay was checked, but will commence again on moisture gaining access to the wood, which is likely to be the case in the cars. Such discolored wood should be rejected for all situations where moisture will again be possible, as it will quickly decay and communicate it to other woods. I recently saw a number of window-frames made up with lumber having on a portion of sap-wood which was discolored; the dampness from the stone window-sill, after a short time, will revive the former growth in the base of the frames, and, the exterior paint retaining the moisture, the growth will be facilitated, and cause decay of the wood.

Many of the ferments I have cultivated from some of the species of wood decayed by different fungi are dissimilar in form and manner of growth; some are confined entirely to a surface-growth of the gelatine, and others germinate in small spheres along the line of inoculation,



those nearest the surface only developing to any size, while those below the air-supply do not increase after a few days. The ferments obtained from decaying hemlock grew and liquefied the gelatine very rapidly from the surface downward; no budding ferments were found but those which grew by fission (bacteria) belonging to the Schizomycetes. An interesting and practical point was, that they grew rapidly in alkaline gelatine, while in that of acid they developed slowly; some cultures in the latter have not grown so much from the 1st of April to July 15th as the same kind of ferments did in alkaline gelatine in ten days after inoculation.