Emil Chr. Hansen 5 Særtryk 1901-1909

594 HANSEN: CONSIDERATIONS ON TECHNICAL MYCOLOGY. of the soil to a large extent. Pure cultures have now been prepared of these bacteria with a view of adding them to soils poor in nitrogen. (Hiltner, in the Agricultural Botanical Institute in Munich, and Moore, in the agricultural experimental station in Wisconsin.) The goal aimed at by our studies is everywhere the same: to obtain greater insight into the development and the activity of these organisms, to be able to control them, to keep injurious forms away, and to favour useful ones. I am only able to dwell upon the points where technical mycology has proved its practical importance in a striking manner. I have, therefore, been obliged to omit a consideration of purely scientific researches, and the vast amount of preparatory works, which are found in all the directions indicated, though there are works of great scientific merit among them. That we have obtained the greatest command ver the micro-organisms in question in the industries concerned in the Icoholic fermentation is not only because this domain was the first to be investigated, but also because the conditions are less complicated than in most of the othei’ fermentation industries. It will, therefore, be readily understood that, with regard to these we are in most cases still occupied with preliminary efforts. In all branches of the industries with which we have here to deal, rapid progress is going on, and each already possesses an exceedingly extensive literature of its own. A glance in Lafar’s “ Technical Mycology,” or still more so in the Handbook which he is publishing together with a body of specialists, will bear this out. II. Long before the effects of biological investigations in these industries had been recognised, physics and chemistry had rendered important service to them. And when at last biological researches were set on foot, the published results were, at first, either disbelieved or opposed by many. It is true that better circumstances have been gradually brought about, still it is only in a few technical laboratories where both biological and chemical researches are carried on side by side that the biologist has got a position equal to that of the chemist. Such a contest has also its good points : it stimulates energy. The Carlsberg Laboratory was the first to give biology a place by the side of chemistry. This is one of its founder’s many great merits. I have