1820.] Scientific Intelligence, 463 



water employed, and the frequent renewal of that water, are 

 circumstances which hkewise contribute to it, each in such 

 proportions,' and with such limitations, as M. Edwards has 

 determined by numerous experiments, which were made with 

 every precaution of the most accurate natural philosopher. 



Frogs can live for several months between 0° (32° Fahr.) and 

 10° (50° Fahr.) in a quantity of 10 quarts of aerated water, 

 which is renewed once every day ; the action which the air of 

 this water exercises on their skin is sufficient for their existence 

 without their lungs being required to be brought into play, but 

 at 10° and upwards they can only live by rising to breathe the 

 air on the surface. If they are confined under the water at 12° 

 or 14° (53° or 57° Fahr.) for example, they perish, whatever care 

 may be taken to renew it, in one or two days ; a running stream 

 will sometimes enable them to support a more elevated tempera- 

 ture under water ; some of them support it as high as 22° (or 72° 

 Fahr.) 



These experiments, independently of their interest with respect 

 to the general theory of the action of air on the blood, explain 

 several singular traits in the economy of these animals, and par- 

 ticularly the extraordinary difference in their manner of living in 

 winter and in summer. 



{To be continued.) 



Article X. 



SCIENTIFIC INTELLIGENCE, AND NOTICES OF SUBJECTS 

 CONNECTED WITH SCIENCE. 



I. Popiilation of Glasgow. 



An actual survey to determine the population of Glasgow was 

 terminated on Feb. 26, 1820. The following is an abstract of 

 the information derived from this survey : 



Population of the 10 parishes within the Royalty ...... 75,169 



Baro7iy Parish. 



Anderston district 7,113 



St. Vincent-street and the Blythswood 



estate district 7,941 



Port Dundas district 7,598 



Calton and Mile-end district 15,616 



Bridgeton district 13,593 



51,861 

 Gorbal's parish, including Hutchesontown, Lauriestown, 



and Tradestown 21,768 



148,798 



