20 



GRAHAM LFSK 



chemistry. One may recall the words of Lavoisier written in his "Ele- 

 ments of Chemistry" (Hubert Kerr, (m) 1799) : 



As the usefulness and accuracy of chemistry depend entirely upon the de- 

 termination of the weights of the ingredients and products both before and after 

 experiments, too much precision cannot be employed in this part of the subject 

 and for this purpose we must be provided with good instruments. ... I have 

 three sets (of balances) of different sizes made by AT. Foritin with the utmost 

 nicety; and excepting those made by Mr. Kamsden of London I do not think that 

 any compare with them in precision and sensibility. 



Lavoisier had a bal- 

 ance which could weigh 

 600 gm. within five mg. 

 and another which was 

 sensitive to within a 

 tenth of a milligram, 

 which were quite up to 

 modem standards of ac- 

 curacy. One may visit 

 the Conservatoire des 

 Arts et Metiers in Paris 

 and see there a notable 

 collection of Lavoisier's 

 apparatus. One sees a 

 gasometer for the accu- 

 rate measurement of 

 gases; there is the cele- 

 brated ice calorimeter of 

 Lavoisier and La Place ; 

 there also are barom- 

 eters of finest workman- 

 ship, set in mahogany 

 supports decorated with 

 gilded 51 agree work, re- 

 minding one of the 

 choicest furniture. 

 These treasures were 



placed in the cellar of the Conservatoire during the bombardment of Paris 



by the Germans in the late war. 



Concerning the gasometers, Lavoisier wrote (Lavoisier, (m) 1799) : 



It becomes expensive because in many experiments, such as the formation 

 of water and of nitric acid, it is absolutely necessary to employ two of the same 

 machines. In the present advanced state of chemistry very expensive and com- 

 plicated instruments are become indispensably necessary for ascertaining the 

 analysis and synthesis of bodies with the requisite precision as to quantity and 

 proportion. 



Fig. 4. Lavoisier and his wife, 

 of a portrait by David. 



From an engraving 



