72 On the Action of Elastic Fluids upon Meat. 



this method the contact of atmospheric air was avoided; 

 but there was this inconvenience, that the whole surface of 

 the flesh was moistened, and that both it and the gas vveye 

 in contact with the water which surrounded the recipient. 



2d. (Experiment made in. an empty vessel, that is to say, 

 which contained neither water nor mercury.) I took bot- 

 tles similar to common wine bottles but with larger necks. 

 I filled them with gas in the pneumatic trough, and intro- 

 duced the meat, keeping the mouth of the bottle above the 

 water. I then corked it as speedily as possible, taking care 

 to lute the cork with pasted paper when the neck of the 

 bottle was put into water. By turning the bottle, the piece 

 of flesh fell to the bottom, where it generally adhered on 

 account of its moisture, Bv this method J avoided wetting 

 the meat; and the gas also as well as that, was not in con- 

 tact with the vapour of the water ; but this method has the 

 inconvenience of bringing some atmospheric air in contact 

 with the meat, and a little of it always gets in w"hen the 

 bottle is corked. This method could not fee follov^'cd when 

 nitrous gas was employed. 



3d. (Experiment over mercurv.) I filled over mercury 

 small recipients of three or four cubic inches, with gas in- 

 tended for the experiment. I then introduced into it small 

 pieces of flesh an inch long, half an inch broad, and twa 

 inches thick; I passed the meat through the mercury with 

 juy fingers, and put it under the receiver; by these means 

 it was preserved from the contact of atmospheric air, and 

 also of the vapour from water, the gas having been obtained 

 over mercury. But I could only operate on a small scale, 

 having but a small quantity of mercury. 



It was necessary always to leave a little water or mercury 

 in the recipient, so that the air when it came to dilate might 

 not escape from the vessels. In the experiments over mer- 

 cury it had this advantage, that the vessels were prevented 

 from being overset. 



The first set of experiments began the 23tb of March, 

 and ended the 4th of Apnl 1508. 



The temperature of the external air was always between 

 the 8th degree of Reaumur and the .5th degree of the same 

 thcrmomettr in the shade. The first extreme was on the 

 oOth of March in the morning, the latter on the 25th of 

 March at noon. 



1st. Oxygen Gas. 



This was obtaiired from nitrate of potass. The experi- 

 ments wei^e made over water. 



The 



