lAfi and Writings ofLct^oifte^ 88 



The laft, and perhaps the moft important of Lavoificr's 

 labours related to animal perfpiration, ou which fubjeet he 

 read a paper before the Academy of Scieocofi oa the 4th c;£ 

 May 1 791. A part of this paper may be fouud in tli^ Mcf 

 moirs of the Academy for the year 1790- 



Lavoifier firft lays it down as an eftabliflied prmciple, that 

 the animal body is maintained by refpiration, perfpiration:, 

 and digeftion. He then examines in a chemical view each 

 of thefe effcci:s, the nature of the perfpiration of the fkin and 

 of the lungs, diflinguiflies the effeds from each other, and, 

 as it vvere> interrogates nature refpeQ:ing the three caufes by 

 which they are produced. He invented an apparatus by 

 which every thing that relates to evaporation externally, and 

 to breathing internally, could be obferved. In conjunclion 

 with Seguin, he made on this fubjecl fame exceedingly dif* 

 licult and laborious experiments., by which he found that a 

 man bv perfpiration lofcs daily 3 pounds 13 ounces ^ that in 

 the caurfe of 24 hours he confumes 33 ounces of oxygen gas; 

 that in the fame period 8 cubic feet of carbonic acid g^as, one 

 third of which confifts of carbon, an-d two thirds of o?:ygcn, 

 are difengaged from the lungs ; that the quantity of water 

 produced in the lungs amounts to i pound 7 ounees,, of whicjj 

 3 ounces are hydrogen, and lo oxygen, and that only 6 

 oimces of water are formed by the perfpiration of the lungs. 

 For thefe experiments he had provided balances which did 

 jiot err half a dram in 125 pounds. 



By thefe accurate and diflicult experiments Lavoifier had 

 obtained great infight into the CAufes of feveraj difeafes, as 

 well as in regard to the means of affilHng the powers of na- 

 ture in curing them, and on that account had refoived to 

 overturn the immenfe cololfus of medical prejiiidices and 

 errors which had been before eftabli (lied. None of his un^ 

 dertakings was of more importance than this, and it is much 

 to be lamented that he did not live to carry it in^Q exeeutioji. 



Between the years 1778 and 1785, he improved and cul- 

 tivated at his own expenfe 240. acres of land in la Vendee, 

 in order that he might promote agriculture by fckting a good 

 example before the farmers.; and his mode of culture was at- 

 tended with fo much fuccefs,. that he obtained a third more 



JuZ of 



