764 



THE POPULAR SCIENCE MONTHLY. 



The velocity with which storms advance 

 is further considered in this paper. It was 

 previously stated that the rate might vary 

 from a stationary condition for many hours, 

 or several days, to the extreme velocity of 

 1,200 miles in a day, or even 57.5 miles an 

 hour. 



By an examination of European maps it 

 appears that storms over Europe travel at 

 an average rate of 26.7 miles per hour, and 

 it was found from examination of American 

 maps that they move at about the same 

 rate in thi.s country. But over the Atlantic 

 Ocean the movement is only 19.6 miles, 

 showing that the velocity is less over the 

 ocean than over the land. 



This proves that the progress of a storm 

 is not merely a drifting of the atmosphere; 

 for, observes the professor, it seems proba- 

 ble that the average progress of the atmos- 

 phere in an easterly direction is as rapid 

 over the Atlantic Ocean as it is over North 

 America. 



IIow K.its and Mice use their Tails. 



To test the correctness of the popular belief 

 that rats and mice use their tails for feeding 

 purposes, when the food to be eaten is con- 

 tained in vessels too narrow to admit the 

 entire body of the animal, a writer in Na- 

 ture made the following experiments : Into 

 a couple of preserve-bottles with n.arrow 

 necks he put as much semi-liquid fiuit-jelly 

 as filled them within three inches of the 

 top. The bottles were then covered with 

 bladder, and set in a place frequented by 

 rats. Next morning the covering of each 

 bottle had a small hole gnawed in it, and 

 the level of the jelly was lowered to an ex- 

 tent about equal to the length of a rat's tail 

 if inserted in the hole. The next experi- 

 ment was still more decisive. The bottles 

 were refilled to the extent of half an inch 

 above the level left by the rats, a disk of 

 moist paper laid upon the surface, and the 

 bottles covered as before. The bottles were 

 now laid aside in a place unfrequented by 

 rats, until a good crop of mould had grown 

 upon one of the moistened disks of paper. 

 This bottle was then transferred to the 

 pia^e infested by the rats. Next morning 

 the bladder had again been eaten through 

 at one edge, and upon the mould were nu- 

 merous and distinct tracings of the rats' 

 tails, evidently caused by the animals sweep- 



ing their tails about in the endeavor to find 

 a hole in the paper. 



Experiments in Bcet-tnltnrc. In the 



course of their experiments on beet-culture, 

 Deherain and Fremy planted some beets in 

 absolutely sterile soils, to which were added 

 from time to time such substances as were 

 thought to be essential for the development 

 of the plant. It was found that the beets 

 continued in the rudimentary state when 

 they received in such soils only distilled 

 water ; they increased slightly in weight 

 when common water took the place of dis- 

 tilled ; their development was greater still 

 when the water contained soluble phos- 

 phates, or salts of potash ; but yet the 

 roots never attained the weight of 100 

 grammes. When for these mineral sub- 

 stances were substituted ammouiacal salts 

 or nitrates, the yield was much better. 

 Normal beets, however, cannot be grown 

 unless to these nitrogenous fertilizers are 

 added phosphates and potash salts. It is 

 worthy of note that, when the beet finds in 

 the soil nitrogen, phosphorus, potash, and 

 lime, it develops as well as in a soil con- 

 taining humus. To establish this point 

 Messrs. Deherain and Fremy compared the 

 produce of two such soils, and found that 

 the beets grown in sterile soil were heavier 

 than those grown in rich soil. 



On examining the beets grown in plots 

 in the experimental garden of the museum, 

 the authors found them to be very poor in 

 sugar, though the soil was very i-ich. From 

 this it follows that deficiency of sugar in 

 the beet is not due to exhaustion of the 

 soil. In seeking the true cause, it occurred 

 to Messrs. Deherain and Fremy to ascer- 

 tain how much nitrogen the beets con- 

 tained, and found it to be very large. 

 Hence it appeared that a soil rich in nitro- 

 geneous matters is unfavorable to the pro- 

 duction of sugar. This conclusion was con- 

 firmed by sundry analyses of beets grown 

 at the museum, at the school of Grignon, 

 and in the departments of Aisne, Nord, 

 and Eure. All the results positively con- 

 firm the observations made by the authors, 

 and their conclusion is that, if beets are 

 now less rich in sugar than formerly in 

 those departments which have long pro- 

 duced them, that fact is not owing to the 

 exhaustion of the soil and its deprivation 



