208 



THE AMERICAN MONTHLY 

 MICROSCOPICAL MANIPULATION. 



[July, 



A Means of Recognizing Frozen. Meats. — M. Maljean 

 ill the Archives de Medecine Militaire, says : This means is 

 based on the aspect of the globules of blood obtained by 

 seraj)ing. In the frozen meats, these globules are colorless, 

 deformed and float in a greenish serum. There is no longer a 

 single one in the normal state. The cold makes the red globu- 

 les burst : then the coloring matter is extravasated in the serum, 

 where k is found again under the form of irregular crystals 

 colored yellowish lirown. 



To Open A Rusty Knife. — We are indebted to The Inventive 

 Age, for the following article and for the use of the cuts with 

 which to illustrate it. 



Take apiece of soft but strong cord, wind it tightly from 

 ten to fifteen times around the closed blades of the knife and 

 of the knife body itself as shown in Fig. 1. Hold or tie the 

 remaining end of the cord to your middle finger. Find a grassy 



spot or soft place and throw the knife down with all your might, 

 just as you do in spinning a top and as shown in Fig. 2. The 

 centrifugal force, caused by the unwinding of the cord and the 

 rapid rotation of the knife will make the blades fly open like 

 the balls on a governor of a steam engine. 



