126 ON EUDIOMETRY. 



mospherkr air in contact with it, precisely as a sulphuret 

 would do. Mr. de Marty asserts, that water thus employed 

 in large quantity, to prevent the process from being too te- 

 jdious, IS an excellent eudiometer, and he has had recourse 

 to it repeatedly. If you have no nitrogen at hand, water 

 may be impregnated with this gas by shaking it in contact 

 with atmospheric air, and leaving it some time in contact 

 with it. By these means it absorbs all the nitrogen it can 

 contain, and the oxigen it takes up with it does not prevent 

 it from absorbing in time, according to the first experiment, 

 that of the air to be analysed. Mr. de Marty avails himself of 

 this absorbing property of water to ascertain whether oxigen 

 gas contain any nitrogen ; for, if it do, water saturated with 

 nitrogen will not absorb the whole. 



8 It is long since Mr. de Marty was acquainted with many 

 of these facts. Some of them, particularly 6 and 7, were 

 known to him, when he composed his Memoir on Eudiome- 

 try ; but he contented hhnself with simply raentionipg the 

 property he had observed in nitrogen. 

 Docs the oxi- Does this oxigeu, continuing to be absorbed, form at 

 gen formal! length an acid? and if so, what acid is it? The solutiau 

 of this problem Mr. de Marty awaits from time and expe^ 

 rience, 

 "Hie experi- With respect to the preceding experiments I shall add, 

 Sade^'with^ that they were all made with the greatest care, in vessels well 

 great care. closed ; that Mr. de Marty has repeated and varied them in a 

 thousand manners ; and that he appears to have observed the 

 most scrupulous accuracy in all. ' 



Mr. de Marty's I shall conclude this letter with some remarks respecting 

 J^^'^^J°"^"-iheMeaioironEudiometry formerly published by Mr. de 

 Marty, of which I have a copy before me in the Spanish Ian* 

 guage, in the Memoriale Liferario for 1795; and of which 

 there is an abstract in the Journal de Physique, year 9. In 

 this abstract, however, many experiments have been omit- 

 ted ; the connexion and detail of which were indispensably 

 necessary to understand the course of the author, and the 

 conclusions at which he arrived : so that in consequence of 

 this omission opinions have been ascribed to Mr. de Marty 

 contrary to those he held, and results the reverse of those he 

 bought to establish. 



For 



