346 



APPENDIX D. 



4. Series of analyses made in 1859, 1860. 



This series is a direct continuation of the third. The waters 

 analysed passed through the same soils through which the waters 

 of the third series had already passed. The fourth series of ex- 

 periments continued from Nov. 16, 1859, to April 12, 1860. 



* The quantity of sand very small. 



