690 



SCIENCE. 



[N. S. Vol. VIII. No. 203. 



sufficiently a current is passed through the 

 oxide by the wire (JS). Within this circuit 

 is a coil ( (?) which upon becoming magnetic 

 draws down the iron bar {E), thus lowering 

 the now incandescent magnesia from within 

 the cylinder. Upon breaking the circuit 

 tiie coil loses its magnetism, and a spring 

 {F) raises the iron bar and magnesia to 

 tlieir former positions. 



As advantages over the ordinary incan- 

 descent lamps Professor Nernst claims that 

 the same amount of light can be furnished 

 at one-third the cost, and as the magnesia 

 allows of being heated to a much higher 

 degree than a carbon filament a purer light 

 is obtained. The successful employment of 

 a clieaper substitute for the platinum is also 

 announced, though the name is not made 

 public. In operating, either an alternating 

 or direct current is used. 



H. Monmouth Smith. 



Hampden-Sidney, Va. 



BOTANY AT THE ANNIVERSARY MEETING 

 OF THE AMERICAN ASSOCIATION. 



II. 



The Biology of Cheese Ripening. Professor 

 S. M. Babcock and De. H. L. Eussell. 

 The most important changes which oc- 

 cur during the ripening of cheese are those 

 which affect the casein, this being gradually 

 transformed, from the firm, elastic and in- 

 soluble conditions found in a green cheese, 

 into the plastic and more or less soluble 

 substance peculiar to a well- ripened prod- 

 uct. The early explanations of these 

 changes were pui-ely chemical, but since 

 the discoveries of Pasteur and others in the 

 field of fermentation they have been at- 

 tributed entirely to bacteria and other 

 micro-organisms. Duclaux suggested that 

 the changes in the casein were due to di- 

 gesting organisms. Later observers have 

 shown that such organisms fail to develop 

 in competition with the lactic acid type of 

 bacteria, which are by far the most promi- 



nent species found in normal cheese. This 

 type appears to be unable to digest casein 

 to any considerable extent when grown in 

 sterilized milk, unless their activity is 

 greatly prolonged by neutralizing the acid 

 as it is formed, in which case again the 

 conditions do not conform to those found in 

 normal cheese. Moreover, the ripening 

 changes in cheese progress at a nearly uni- 

 form rate for a long time after bacterial de- 

 velopment has greatly declined. The au- 

 thors of this paper were unable to reconcile 

 the many appai-ent discrepancies of the 

 biological theorj'^ of cheese ripening until 

 they attempted to sterilize milk for their 

 experiments by the addition of mild anti- 

 septics, such as ether and chloroform, 

 which could afterwards be removed and 

 thus avoid changes which might be pro- 

 duced by boiling the milk. Such milks, 

 although sterile, passed through changes 

 similar to those that occur in cheese. As 

 the agents used in this case discriminate 

 between organized and unorganized fer- 

 ments, it is evident that milk contains an 

 unorganized ferment capable of digesting 

 casein. This enzyme is inherent in the 

 milk itself. The authors have given to 

 this ferment the name galactase, and they 

 believe it plays an important role in the 

 proteolj'tic changes that occur in the ripen- 

 ing of cheese. 



Fermeniation without Live Yeast Cells. 



Katherine E. Golden and Carleton G. 



Ferris. 



This paper first summarizes the rather 

 extensive and contradictory literature, be- 

 ginning with E. Biichner in 1897, who 

 claims to have induced active fermentation 

 of various sugars with a sterile extract ob- 

 tained from dried yeast by filtration 

 through a Berkefeld filter. Biichner's 

 method was followed in the preparation of 

 the yeast. In filtering, the fluid was first 

 passed twice through three thicknesses of 



