CULTIVATION AND PRESERVATION OF PENICILLIA 61 



been extensively used in the description of species of this group and these 

 will be more or less fully discussed. 



MEDIA USED IN EARLIER STUDIES 



Raulin's Solution 



The following solution, proposed by Raulin (1869) in his study of the 

 biochemical activity of Aspergillus niger, has been widely used: 



Water 1500.0 grams 



Cane sugar 70.0 grams 



Tartaric acid 4.0 grams 



Ammonium nitrate 4.0 grams 



Ammonium phosphate 0.6 grams 



Potassium carbonate 0.6 grams 



Magnesium carbonate 0.4 grams 



Ammonium sulphate . 25 grams 



Zinc sulphate 0.07 grams 



Iron sulphate 0.07 grams 



Potassium silicate 0.07 grams 



Dierckx's neutral Raulin's fluid as given by Biourge (1923, p. 43) follows: 



1 . Magnesium carbonate . 40 gram 



Tartaric acid 0.71 gram 



Triturate in a mortar with a few drops of distilled water and add quickly to a 

 flask of distilled water; make up to 100 ml. 



2. To a liter flask with 800 to 900 ml. distilled water add: 



Sucrose • • ■ 46.60 grams 



Ammonium nitrate 2.66 grams 



Ammonium phosphate 0.40 gram 



Potassium carbonate 0.40 gram 



Ammonium sulphate 0.16 gram 



Zinc sulphate 0.04 gram 



Iron sulphate 0.04 gram 



3. Add 66 to 67 ml. of the magnesium tartrate solution (1) to the mineral salt- 

 sucrose solution (2) and make up to 1,000 ml. with distilled water. 



Biourge (1923) noted that the purpose of this revision was to eliminate 

 the free tartaric acid of Raulin's original formula by using only enough to 

 dissolve the magnesium carbonate. He appended in a note that he used 

 0.27 gram magnesium carbonate and 0.40 gram tartaric acid and ground 

 these in a mortar with a few drops of water until dissolved, then diluted 

 at once to a large volume to stop crystallization. Biourge regarded this 

 as a good substratum when 10 percent gelatin was added, but as an in- 

 different or even poor nutrient when agar was used to produce a solid 

 medium. 



Zaleski (1927) used the same basic formula in describing his species, but 



