PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 733 



to be the effect of refraction, a,slronomcrs must rectify some results 

 arrived at recently in relation to the sun. ; 



The Locomotion of Fishes. 

 Mr, Ferdinancl Monoyer says : The movement of fishes through 

 the water takes place by the action of the tail, and principally of 

 the caudal fin. When the progression is rapid the other fins play 

 no part in locomotion. When the fish wishes to stop, it does so 

 as an oarsman would, by producing " back-water," which it effects 

 through its pectoral fins. The others may be employed in this 

 latter operation, but their only use is to prevent the fish from 

 turning round on its transverse axis. On the other hand, the 

 observations of Dr. W. Rowell lead him to the conclusion that 

 some species of small fish bend the whole body in propulsion. 



The Cattle Plague. 



No remedy has yet been discovered for this great scourge. The 

 ofiicial report of cases of cattle disease in Holland for several weeks 

 is as follows : Nov. 3, 1866, total for a week, 1,443 , Nov. 10, 

 1,551; Nov. 17, 1,595 ; Nov. 24, 3,257, and Dec. 1, 7,162. The 

 last number is more than dou])le that recorded in December, 1865. 

 There has been such an alarmiil^ increase of cases that certain dis- 

 tricts have been entirely isolated. Reports are rife regarding the 

 re-appearance of the disease in one district in Great Britain. Mr. 

 G. Leeman, M. P., stated, at a dinner in connection with a fat 

 stock show at York, that the pecuniary loss of the agricultural 

 community of Great Britain, in consequence of the cattle disease, 

 had been estimated at ^£3,500,000, and the loss in stock at 5 per 

 cent upon 5,000,000 head of cattle. 



The Eichness of Milk. 



The milk last drawn from the udder of a cow is richest in cream, 

 because partial sepaiation of the cream from the milk takes place 

 in the udder, and the milk "which has been deprived of its cream 

 is first drawn. Dr. Anderson found by actual analj^sis that in one 

 instance the proportion of cream in the last to that in the first cup 

 drawn was as 16 to 1. The quality of milk is impaired if the cow 

 is subjected to too much exercise, because her respiratory organs 

 are then brought into greater play, and the excess of oxygen in- 

 spired unites with particles which otherwise would form the butter 

 fcund in cream. For this reason morning's milk is always richer 



