I tfv) Fluids «'» Nil tvttufmit Hrai iIew»WifrJ}- 



An Jccouttt offeveral new Experiments en Heat, ivilh occaftonal Ri'vtarJts and Ohfirvatkns ; anil 

 Ccnje3ur(s rcfpeSfing 'Chemical Affinity and Solution-, and the Mechanical' Principle cf Animal 

 Life. By Bli\-JAMIWt Count of RumI^QKD'^- 



A 



T the end oJ" a French Tranflation of the firft edition of Count Rumford's Seventh 

 Efl'av-, byTiofenbr l'i£tet, that Tianflator added the following extract of one of the Count's 

 private letters to him', dated June 9, \']c,-j : "I fhould have been much furprifed if my 

 " Seventh EfTay had not interefted you ; for in my life I never felt plcafure equal to that 1 

 ** enjoyed in making the experiments of which I have given an account in that perform- 

 " ance. You will perhaps be furprifed when I tell you, that I have fupprefTed a whole chap- 

 " ter of interefting fpeculation, merely with a view of leaving to others a tempting field of 

 " curious inve!>igation untoi^ched, and to give more efFecl to my concluding rcfleftion, 

 '' which I confider as'Deing by far the moft important of anv I have ever publifhed," As 

 thefe aflertions were not originally intended fur the public eye, the worthy author found 

 his fituation altered with regard to the philofophical world by this communication ; and 

 with a very honourable degree of delicacy Conceived that it became his duty to let the pub- 

 Jic know v.'ith prccifion how far he had carried his enquiries in the inveftigation of the 

 fuhjed of that EfTay, inftead of giving obfcure hints of important fa£l;s kept in refcrve, and 

 apparently to be brought forward, when others might make tiifcoveries of the fame kind. 

 The work before us contains the matter in queftion. 



The experiments and obfervations contained in this Second Part are as follow : 

 Chap. I. When a quantity of water was frozen in a glafs jar by placing the vefTel in a 

 freezing mixture, it was always obferved that, as the ice firft began to be formed at the 

 fides of the jar, and gradually increafcd in thicknefs, the portion of water in the axis of the 

 jar which lad retained its fluidity, being compreffed by the expanfion of the ice, was forced 

 upwards towards the end of the procefs, and formed a pointed projection or nipple, which was 

 fometimes above half an inch higher than the reft of the upper furface of the ice. This 

 ft6l induced the Count to make experiments relative to the defeft of condiicSting power in 

 fluids downwards. For, if a fluid be poured upon this cake of ice fo as to cover the whole 

 mafs, and a heated folid be then fufpended at a fmall diftance from the papillary protuberance, 

 it is evident that this iaft, if melted, will derive its fluidity from the tranfition of heat,' 

 through the fluid of which the conducing power or its abfence was meant to be afcer- 

 tained. 



In an experiment with fine olive oil, the cake of ice or congealed water was three inches 

 thick, four inches and three quarters in diameter, and the pointed proje£tion rofe half an 

 inch above the upper furface. The temperature of the apartment was 31 degrees of 

 Fahrenheit, and the external part of the jar as high as the ice was furrounded with a mixture 

 of pounded ice and water. In this fituation of the apparatus, fine olive oil, previoufly cooled 

 to 32 degrees, was poured into the jar till it ftood at the height of three inches above the 

 liirface of the cake of ice. 



* Abridged from the Seeond Part of his Sevc)ith Experiroental Effay. 



A folid 



