334 



Mr. G. Gore on the Thermo-electric [Feb. 23, 





Grains diluted 



No. 



to 20 ozs. 



i. 



. . . ou 



2. 



... 100 



3. 



... 200 



4. 



... 400 



5. 



... 800 



6. 



. . . 1600 



7. 



. . . 2000 



8. 



. . . 2727 



Acetate of Sodium. 



Value of 

 Deflection 

 •0016 

 •0070 

 •0198 

 •0594 

 •1328 

 •2202 

 •2850 

 •2997J 



Hot plate positive. So- 

 lution alkaline to test- 

 paper. 





Grains diluted 



No. 



to 20 ozs. 



1. 



50 



2. 



... 100 



3. 



... 200 



4. 



... 400 



5. 



... 500 



6. 



... 800 



7. 



. . . 1000 



8. 



. . . 1600 



9. 



. . . 2000 



Acetate of Zinc. 



Value of 

 Deflection 

 ■0001 

 •0006 

 •0016 

 •0025 

 •0020 

 •0020 

 •0012 

 •0004 

 •0001 



•Hot plate positive. 



Crystallized Tartaric Acid. 



The hot plate was negative. Eight different solutions, varying in 

 strength from 50 to 3200 grains in 20 ounces by measure of the solution, 

 were tried ; but very feeble currents were obtained, and the plates were 

 not tarnished. 



Crystallized Citric Acid. 



The hot plate was negative. With a series of seven solutions, varying 

 in strength from 50 to 3200 grains in 20 ounces of liquid, more feeble 

 results, even, than those with tartaric acid were obtained, and the plates 

 were not tarnished. Probably, with this substance and with others where 

 the resulting currents were very feeble, more distinct effects would be ob- 

 tained by employing a galvanometer of much greater electrical resistance. 



Several experiments similar to those already described were made with 

 the apparatus shown in fig. 3. The apparatus consists of a glass beaker 

 containing the liquid, and two platinum electrodes — A being a disk of pla- 

 tinum rivetted to a platinum wire enclosed by a glass tube, B, and C a 

 platinum crucible (for receiving the boiling water) with a platinum wire 

 rivetted to it. 



Experiment 1. — With a solution of 100 grains of citric acid in 2 ounces 

 of distilled water, the hot platinum cup was negative, the value of the tem- 

 porary deflection being *0007. 



Experiment 2. — With 100 grains of tartaric acid in 2 ounces of water, 

 the hot cup was negative, value of deflection -0001. 



