2(58 HuRgnrian EreaJ.—'Keiv Eudicmrttr. 



water. This is poured through a fievc into one end of the bread-trough, and three quarts more 

 of warm water are poured through the fieve after it, and what remains in the fieve is well 

 prtflcd out. This hquor is mixed up with fo much flour as to form a mafs of tlie fize of 

 a Iarj;e loaf: this is (Irewcd over with flour, the fieve, with its contents, is put upon it, and 

 then the whole is covered up warm, and left till it has rifen enough, and its furface has 

 begun to crack : this forms the leaven. Then fifteen quarts of warm water, in which Cx 

 lianilfuls of fait have been difTolved, are poured through the Ceve upon it, and the neceflTary 

 qujiitity of fluur is added, and mixed and kneaded with the leaven : this is covered up 

 warm, and left for about an hour. It is then formed into loaves, which are kept in a warm 

 •room half an hour ; and after that they are put in the oven, where they remain two or 

 three hours, according to the fize. The great advantage of this ferment is, that it may be 

 made in great quantities at a time, and kept for ufc. Might it not on this account be ufe» 

 ful on board of iliips, and likewifc for armies when in the field ? 



VIII. 



Dcfcrlption and life of an Eudiometer luith Siilphuret of Pot-AJli. By Citizen CuTTON ' 



N, 



ATITRAL pliilofophers and chemifts have long been defirous of pofleirmg an eudio- 

 meter which might accurately fliew the quantity of oxygenc mixed in any kind of gas. Citi- 

 zen Berthollet has clearly fliewn, in his late leflbns to the Normal School f, that the eudio- 

 jneter of Scheele, which he with juftice confiders as the beft, has neverthelefs great dcfe£ls j, 

 becaufc the abforption requires feveral hours, and becaufc there is a decompofition of water 

 towards the end, which confequently difengages hydrogene gas, and renders the meafure of 

 abforption doubtful. 



This confideration induced me to feek a material which might immediately, and with con- 

 venience, afford a refult more to be depended on than thofe obtained by nitrous gas, hy- 

 drogene gas, phofphoTus, and the mixture of fulphur and iron ; the only fubftances which 

 have been, as far as I know, hitherto ufed or propofed for that purpofe. 



The fulphuretof pot-alh appeared to me to deferve trial in this refpe£l. I well knew that 

 Tit the ordinary temperature it is only fufceptible of a combination dill more flow and in- 

 fenfible than the mixture of fulphur and iron moiftened ; but I prefumed that by raifing the 

 temperature, merely by the approach of a fmall taper, the aition of cliemical affinity might 

 be fo much favoured as to determine rapidly an abforption wliich in that cafe would not be 

 -affefled by any foreign circumftance. 



The efTeit has completely juftified my conjeflure ; fo that nothing more remains than 

 to dcfcribe the apparatus required to form this eudiometric inftrument. I thought that the 

 revcrfed retort, or inflcdled receiver (recipient cornu) as I have named it in the article Jir of 

 the Encyclopidie Methodique, I. 706, would unite finiplicity, convenience, and every dc- 

 firab!e advantage. The experiment was made in the laboratory of the third divifion of the 

 Polytechnic School, according to the following defcription: 



'• Jdirral dc I'Ecolt Polyttchniq'.ie, IT. 166. 



■\ Svoucc dci Ecclci NormaUi, &c. torn. v. p. 73> 



A B, Plat? 



