March 10, 1899.] 



SCIENCE. 



379 



tact Resistance of (^arbon and Copper Brushes 

 and the Temperature Rise of the Commutator.' 

 He finds tliat the contact resistance decreases 

 with increase of current density, especially with 

 higher velocities of commutator surface ; thus, 

 with a velocity of 368 meters (1205 ft.) per 

 minute, the resistance per sq. cm. is for .7 amp. 

 per sq. cm. .6 ohm., while for 10 amp. it be- 

 comes only .1 ohm., beyond which point it is 

 nearly constant. He finds also that for a given 

 current density the resistance increases with 

 speed to a maximum, and then decreases for 

 higher speeds ; this he accounts for by suppos- 

 ing an unfavorable relation, between the weight 

 of the brush and the periodicity of the vibra- 

 tions from passing over the segments ; this 

 theory is upheld by the fact that the same max- 

 imum appears at a lower speed for the heavier 

 copper brush. A highly polished metal surface 

 gives a higher resistance, which oiling increases 

 still further. He mentions eddy currents as pro- 

 ducing losses in the segments, and gives formula} 

 for the friction losses and the rise of the tem- 

 perature. 



F. C. C. 



ENZYMES AS REMEDIES IN INFECTIOUS 

 DISEASES. 



DxJElNG the past year Drs. R. Emmerich and 

 Oscar Loew have been engaged upon an inter- 

 esting problem in connection with enzymes as 

 remedies in infectious diseases. The work was 

 carried on in Munich, and as yet the results have 

 not been published in full. We are indebted to 

 Dr. Loew for the following facts in regard to the 

 investigations : It has been surmised by Nencki 

 and by Pfeiffer that the substances leading to 

 recovery from infectious diseases, and producing 

 immunity from them, belong to the enzymes. 

 The latter author believed that these enzymes 

 . are prepared by the animal organs and not by 

 bacteria themselves. Dr. de Schweinitz has 

 observed an enzyme in cultures of the hog 

 cholera germ which had a potent action in 

 rendering guinea pigs insusceptible to this dis- 

 ease. However, this enzyme exhibited poison- 

 ous action in but little higher doses than 

 necessary for immunizing. 



Recently Emmerich and Loew have proved 

 that certain kinds of bacteria, for example, 



Bacillus pyocyane-us, produce enzymes which not 

 only dissolve these bacilli themselves, but also 

 other microbes, such as the germs of cholera, 

 typhoid fever, anthrax, diphtheria, black 

 plague, stapthlococci and probably also gon- 

 ococci. The germs of tuberculosis and many 

 others are not affected by this enzyme within 24 

 hours. Micrococcus prodigiosus can also pro- 

 duce a bacteriolytic enzyme, which does not ap- 

 pear to act so favorably as that of the Pyocyaneus. 

 The Micrococcus erysipelatos produces one, but 

 this is associated, as in many other cases, with 

 very poisonous qualities.* Emmerich and Loew 

 have demonstrated that in a rabbit first infected 

 with anthrax and then treated with subcutane- 

 ous injections of the concentrated enzyme of the 

 Bacillus pyocyaneus the anthrax bacilli in the 

 spleen are found completely broken up and 

 partly dissolved, exactly as it can be observed in 

 vitro when a dose of millions of anthrax and the 

 other named bacilli are transferred into a few 

 cubic centimeters of the concentrated and puri- 

 fied pyocyaneus enzyme. The latter enzyme 

 can, by combination with an animal protein, be 

 transformed into an immunizing substance. 

 The authors have succeeded in obtaining both 

 these agencies in a durable solid form. Thus 

 the time seems near at hand when the treat- 

 ment with serum will be replaced by a cheaper 

 and simpler method, at least in certain cases. 

 B. T. Galloway. 



SCIENTIFIC NOTES AND NEIVS. 



The refusal of Congress to establish a perma- 

 nent census bureau for the proper conduct of 

 the work has had its natural sequence in the 

 appointment of a politician as Director of the 

 Twelfth Census. The best that can be said of 

 ex-Governor Merriam is that he had a credit- 

 able record as Governor of Minnesota. The 

 New York Evening Post speaks of the appoint- 

 ment as follows : ' ' Mr. Merriam is appointed 

 Director of the Census simply because there 

 was no other good office vacant at home or 

 abroad. He has never had any experience as 



*Tlie bacillus of the black plague, that of tuber- 

 culosis, and other kinds, seem incapable of producing 

 bacteriolytic enzymes, at least not to any noticeable 

 degree, and the serum of black plague has, therefore, 

 been applied without success in the cases at Vienna. 



