90 Biological Scction, American Chemical Society [Oct. 



and carbohydrate, plus Röhmanii's salt mixture, for a period of 80 

 days. Most of the rats lost weight during the last three weeks. 

 To the basal ration during 35 days immediately following the 80 

 days on the basal diet alone, 5 c.c. of a Solution of meat extract, 

 plant extract, or whole milk, were alternately added, the nitrogen 

 and sodium chloride of the three accessories being equal. When 

 meat extract or milk was fed, a marked increase of weight was ob- 

 tained. Eleven young white rats were fed for 35 days on a basal 

 diet, plus one of the three accessories. The stimulating efTect of 

 milk as shown by Hopkins was noted. The meat extract also acted 

 as a stimulant, while the plant extract showed little, if any, stimulat- 

 ing action. The milk and meat extract gave the biuret reaction 

 and heavy precipitates with phosphotungstic acid, but the plant ex- 

 tract did not give either of these reactions. The meat extract, which 

 is a hydrolyzed product practically free from fat and carbohydrate, 

 seems to possess the stimulating properties similar to milk, a natural 

 product. That the calories are not the sole guide in feeding experi- 

 ments, in harmony with the work of Hart, Hopkins, Osborne and 

 Mendel, and others, was noted. The rats gained in weight on 

 a smaller number of calories when milk or meat extract was ingested. 

 No gain in weight was obtained with a larger number of calories in 

 the food ingested in the absence of milk or meat extract. 



A time recorder for kymograph tracings. Oliver E. Clos- 

 SON. {Research Laboratory of Parke, Davis and Co., Detroit, 

 Mich.) It is at best a tedious Operation to find the projection of 

 the time record on the different graphs as ordinarily traced upon 

 smoked paper. The time interval can easily be recorded by a fine 

 line, entirely across the paper by the following simple device. A 

 fine spring wire stretched two to three mm. from the smoked 

 surface will strike the smoked paper on the rebound and remove 

 a fine line of soot, when picked by the armature of the time-signal 

 magnet. By a little adjustment, a single distinct line is recorded at 

 each closure of the circuit. If it is inconvenient to adjust any 

 recorder to write perpendicularly to the base line, it is a simple 

 matter to make the adjustment so that the time line will be parallel 

 to any such line. 



Apparatus for studying oxidases. Oliver E. Closson. (Re- 



