85 



temperature variation. By plotting a curve of the sub-tangent of the vi«cn>>ity- 

 temperature curve against the temperature, a subsidiary curve was formed which 

 should, in all the types of formula proposed, be a straight line, but which turned 

 out to be a parabola. On determining the constants of the parabolic equation 

 and integrating this to obtain the equation of the viscosity-temperature curve, 

 a formula was deduced which represented the experimental results to within the 

 limits of experimental accuracy. This formula was an exponential one, the 

 exponent being the inverse tangent of a linear function of the temperature. 

 Reasons were given for believing that this would represent the temperature 

 variation of the viscosity of any litjuid. 



The Effect of Grape-Sugar Upon the Composition of Certain Fat- 

 Producing Bacteria. By Robert E. Lyons. 



It has been observed by Dr. E. Cramer •■ and otherst in studies upon the com- 

 position of bacteria, that the same micro-organism grown upon Peptom and 

 (Jrape-sugar Agar-Agar produces in eaeli case different quantities of nitrogenous 

 substances and matter which is soluble in alcohol and ether. 



In this same direction Ducleauxj demonstrated that yeast cells grown upon 

 a material containing grape-sugar produced fat, while the same yeast grown upon 

 pure nitrogenous material did not produce fat. 



To study how grape-sugar afl'ects the quantities formed of nitrogen, ash, fat 

 and matter to be extracted by nfeans of alcohol and ether, three varieties of cap- 

 sule bacilli were selected : 



Pfeiffers' Capsule Bacillus. 

 Fadenziehender Capsule Bacillus. 



I No. 28 Capsule Bacillus. 



*Dr. E. Cramer — " Zusammensetzung der Bacterien in ihrer Abhiing-igkeit von dem 

 Niihrmaterial." Arch, fiir Hygiene— W, 151-191. 



t Tayosaka-Nishimura— " Zusammensetzungeines Wasserbaoilliis." Arch, fiir Hygiene 



;,s, .318-333. 



+ Dueleaux— " Sur la nutrition interaoellulaive." Ann. de Tlnstitute Pasteur— 1889 No. 

 8, p. 413. 



Fadenziehender and No. 28 are forms from the water of the River Lahn, near Mos- 

 bourg. 



