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XIII. Experiments proving that Mariotte's Lata is applica- 

 ble to all Kinds of Gases ,• and to all Degrees of Pressure 

 under which the Gases retain their aeriform State. By 

 H. C. Oersted*. 



r rHE law of Mariottef, according to which the spaces oc- 

 -*• cupied by a certain quantity of gas or air are found to 

 be in an inverse ratio of ihe degrees of pressure which they 

 suffer, has hitherto been demonstrated by strict experiment for 

 very small degrees of pressure only. Several men of science 

 of the first class have assumed this law as being applicable to 

 every degree of pressure, in exact conformity with nature : 

 others, and among these Jacob Bernoulli and Euler, enter- 

 tained the opinion that the spaces decrease in a smaller pro- 

 gression than that in which the pressure is increased ; and if, 

 in fine, we refer to the small number of experiments made 

 with high powers of pressure, the proportions of space seem 

 to decrease in a much greater progression than that in which 

 the pressure increases. Sulzer, a well-known German writer, 

 has published, in the Transactions of the Academy of Berlin, 

 experiments advancing to a pressure of eight atmospheres. 

 Robison, a very respectable English writer, made similar 

 experiments. — The following table furnishes the results ob- 

 tained by both. 



Sulzer 



's Experiments, 



Robison's Experiments 



(complete series). 



with dry air. 



Density. 



Compressing Powers. 



Density. 



Compressing Powers. 



1-000 



1-000 



1-000 



1-000 



1-091 



1-076 



2-000 



1-957 



1-200 



1-183 



3-000 



2-848 



1-335 



1-303 



4-000 



3-737 



1-500 



1-472 



5-500 



4-930 



1-714 



1-659 



6-000 



5-342 



2-000 



1-900 



7-620 



6-490 



2-400 



2-241 







3-000 



2-793 







4-000 



3-631 







6-000 



5-297 







8-000 



6-835 







* Read before the Royal Society of Copenhagen, and published in 

 Schweigger's Journal, N.R. Band xv. p. 352. 



f It is well known that this law was first deduced from the experiments 

 of the famous Boyle, by his friend Richard Town ley : nevertheless I have 

 called it by the name of Mariotte, who discovered it at the same time by an 

 experiment of his own, as it is commonly known by this appellation. — O. 



Captain 



