52 CHEMICAL DISCOVERY AND INVENTION 



in 1892 related to the question long under discussion as to the 

 influence of the presence of air on fermentation by yeast. At 

 that time Pasteur's view was predominant, namely, that yeast, 

 as an organism capable of living either in contact with air 

 (aerobic) or without it (anaerobic), behaves actively as an 

 alcoholic ferment only in the absence of free oxygen. Brown 

 showed, however, that Pasteur's view was untenable and that 

 the presence of oxygen stimulates rather than retards the 

 fcrmentive activity of yeast. 



In 1912 he discovered that the seeds of the barley and other 

 plants of the GraminacecB are covered with a membrane which 

 has the remarkable power, when immersed in various solutions, 

 of permitting the entry into the seed of some substances, while 

 excluding others. 



Thus the membrane completely excludes sulphuric acid, and 

 caustic soda so long as the membrane is unaltered, while it 

 allows iodine to pass in slowly, as indicated by the deep blue 

 colour assumed by the starch grains within. This property of 

 selective permeability does not appear to be a function of living 

 protoplasm, as it is exhibited after the seeds have been immersed 

 in boiling water, and it is evidently not a case of ordinary liquid 

 diffusion by which crystalloids are separated from colloids. 



These results bear upon not only the question of what happens 

 when barley is steeped in water as in the process precedent to 

 germination, but raise further questions in connection with the 

 already much-debated theories of solution. 



II. THE MUNICIPAL SCHOOL OF TECHNOLOGY, MANCHESTER 



The Municipal School of Technology, like so many other 

 educational institutions which within the last generation have 

 risen into a position of prominence, arose out of a comparatively 

 humble origin. 



The earliest of the Mechanics' Institutes, which owed their 

 existence to the enlightened and far-seeing philanthropy of such 

 men as Dr. Birkbeck and Lord Brougham, were established in 

 London about 1820. During the greater part of the nineteenth 

 century these Institutes provided, by means chiefly of evening 

 classes, almost the only opportunity for those who felt the dis- 

 advantages of ignorance, to make up for the deficiencies in their 

 early training. Nowhere in this country did the establishment 

 of Institutes of this kind proceed more rapidly and successfully 



