356 



Messrs. A. R, Ling and D. R. Nanji. 



the date in Prof. Hansen's handwriting. The following is a copy of the script 

 on each label : — 



Sacch. Pastorianus I, Hansen, 17/9/87. 

 Sacch. Pastorianus II, Hansen, 17/9/87. 

 Sacch. Pastorianus III, Hansen, 17/9/87 

 Sacch. ellipsoideus I, Hansen, 17/9/87. 

 Sacch. ellipsoideus II, Hansen, 17/9/87. 

 Sacch. exiguus, 17/9/87. 

 Sacch. cerevisiee I, Hansen, 17/9/87. 

 Carlsberg Unterhefe, No. 2. 17/9/87. 



As already observed, the contents of each flask consisted of a dry cotton- 

 wool plug and the plugs were in every case of a brownish colour. Apparently, 

 the cultures had originally been made in the manner described by Prof. 

 Hansen in his ' Studies in Fermentation,' 1896, p. 74, thus : — 



" For sending pure cultivated yeast in an absolutely pure condition, and in 

 such a manner that its multiplication can be effected easily and with 

 certainty, I have likewise made use of the following method, which has also 

 given good results : — To the small cylindrical flasks generally known as 

 Freudenreich flasks I have added a side tube (see fig.). The tube, A, on the 

 hood is, as usual, filled with cotton-wool; a firm layer of cotton- wool is 

 placed at the bottom, E, of the flask, and a plug is inserted in the neck, B. 

 The side tube is also plugged with cotton- wool, and the flask is then sterilised 

 by heating it for two hours at 150° C. When it has cooled, the tube is joined 

 to the rubber of a two-necked flask, in which the yeast has been grown, and 

 a drop of the fairly thick yeast is poured on to the layer of cotton-wool, E. 

 The tube is then closed by a stopper, D, of asbestos card, previously sterilised 

 in a flame, and the stopper is then coated over with a layer of sealing-wax, C." 



In order to ascertain if the yeasts were still alive, a little sterile sweet wort 

 was introduced into each flask by the side tube after removing the wax and 

 cotton-wool. The flasks were then kept in an incubator at 25° until gi'owth 

 appeared. A thick sediment formed after some time, and when this was 

 examined if was found in every case to contain yeasts, sometimes contami- 

 nated with bacteria. Plate cultures were made on wort gelatin containing 

 0'4 per cent, of tartaric acid, and ultimately pure cultures of the several 

 yeasts were obtained. 



The cultures were identified by Hansen's spore method, the results being 

 shown in the following Table : — 



