K.— BOTANY 217 



a fungus in times of necessity need not be stressed, for ammonium salts 

 can be obtained from the air and carbohydrates from the hydrolysis of 

 wood. 



Towards the end of the War, H. Pringsheim and S. Lichtenstein 

 added a non-pathogenic strain of Aspergillus fumigatus to straw moistened 

 with a small amount of ammonium salt in solution. The fungus grew 

 well and raised the total protein content of the straw from one to eight 

 per cent. The mouldy straw was dried and used for feeding sheep, cattle 

 and rabbits. Fed experimentally to sheep it was found that forty per 

 cent, of the protein was assimilated. 



J. R. Sanborn has recently shown that species of Oidium and Monilia 

 concerned in the formation of pulp and paper-mill slimes produce doughy 

 and somewhat rubbery growth with great rapidity in media rich in 

 carbohydrates, and has succeeded in producing a satisfactory parchment- 

 like membrane from them. R. O. Herzogm and A. Meier took out an 

 American patent in 191 5 for making a leather substitute by tanning 

 a similar growth formed by Bacterium xylinum, B. xylinoides or Mucor 

 Boidin. 



In the search for acetone to produce cordite during the War, A. Fern- 

 bach and E. H. Strange patented a method for its production (together 

 with acetates and pyruvates) with Mucor Rouxii. The full story of 

 acetone production in this country with its military, political and financial 

 results is one of the romances of microbiology. 



Artificial ageing of green coffee has been attempted by a number of 

 methods, many of which have been patented. F. W. Robison in 1919 

 patented a method of using moulds (Aspergillus ochraceus) for this purpose. 

 ' A green Java or a Brazilian Santos can be transformed in ten days 

 from a characteristic high-grade rough coffee to a smooth, creamy, Java- 

 like coffee.' 



From the nuclein of yeast nucleic acid is obtained and combined with 

 silver, calcium or sodium. The compounds thus formed show marked 

 bactericidal action on injection, together with a large increase in leuco- 

 cytes and are not irritable. 



Yeasts have also been used in the manufacture of synthetic plastics, 

 and for assisting the growth of organisms in sewage disposal plants. 



To turn to the opposite extreme. The enzyme invertase is prepared on 

 a commercial scale from yeasts. Several processes have been devised 

 to use it for inverting sucrose in the manufacture of various syrups. 

 It is also used in the American candy trade because sweets made from 

 fructose are more tenacious when wet and more retentive of moisture than 

 when made from cane sugar. As a result of increased solubility in the 

 syrup phase the growth of micro-organisms is retarded or prevented and 

 thus the ' explosive ' fermentation which causes so much financial loss 

 by bursting and shattering candy is eliminated. 



Many of the processes here outlined have been patented. It is not 

 my purpose to comment on this beyond saying that a great deal of myco- 

 logical and bacteriological information lies hidden in patent specifications. 

 All who have tried to find their way amongst these know how Herculean 

 the task is — I have merely skimmed the surface, as may be judged from 



