On Air Balloons. ^' 



that of animals, would seem to pervade the very substance of 

 those animals whose food contains much oil. Thus, we find 

 sea-birds, whose constant food is fish, taste very strongly of 

 fish ; and those who live on that kind of food only during 

 certain times of the year, as the wild duck, have that taste only 

 at such seasons. This fact is so well known, that it was hardly 

 necessary to put it to the test of an experiment ; yet, I took two 

 ducks, and fed one with barley, the other with sprats, for about 

 a month, and killed both at the same time : when they were 

 dressed, the one fed wholly on sprats was hardly eatable, it 

 tasted so strongly offish." — Hunter's Observations on Digestion, 

 p. 177. 



From the preceding detail, it would appear that the patho- 

 logical examination of fat furnishes us much matter for reflec- 

 tion on the changes that may be produced in fat, in the living 

 state, by the process of digestion, as also the probable causes 

 of the transmutation of diseased appearances, and the sudden 

 change that sometimes takes place in the character of acute 

 diseases. 



Leaving these discussions to the doctors for *' Non nostrum 

 inter vos tantas componere lites," we shall proceed to the object 

 of our inquiry, viz. corpulency and its consequences. 



[To be continued.] 



On the Origin of Air Balloons, 



S Uj ^ Bristol, December 20,1827. 



It is rather remarkable that so many books having been 

 published on the subject of balloons, and so much money ex- 

 pended in useless experiments to discover a method of guiding 

 them with precision, no one that I know of has as yet pointed 

 out the origin of the invention, which will be found, copiously 

 detailed, accompanied by a figure explanatory, in a folio volume, 

 dedicated to Leopold L, by Francesco Lana, a Jesuit of Brescia ; 

 and published by Rizzardi, of Brescia, MDCLXX. The prin- 

 cipal part of this volume is taken up by eight chapters on the 

 subject of telescopes and microscopes, in which he gives di- 

 rections for grinding lenses, and reflectors of metal, with plans to 

 give the true hyperbolic, elliptic, and parabolic curves, the latter 



