192 [Assembly 



grapes grew ; this moisture was felt by the vines, above and be- 

 low the earth on the banks of the brook, by the roots, leaves and 

 branches. Italy for nearly two thousand years, and to this day, 

 produces fine grapes, her soil and climate are congenial to them. 

 From Italy, tlie practice of irrigation extended into the south of 

 France, into Spain, then into Britain. In the states of Lom- 

 bardy the waters of all the rivers belonged to the state. In those 

 of Venice the government extends its claims to that of the small- 

 est springs, and even to collections of rain water, so highly for 

 the use of the cultivator is water of every kind valued in the 

 north of Italy. It is paid for by the peasants, to the state, in the 

 shape of tax, according to the quantity used. Thanks to the 

 wisdom and foresight of our ancestors, which are evinced in the 

 happy form of government they framed for and left us, we are 

 not so restricted in the use of the two essential elements, air and 

 water. The former we can freely use as it hangs over and en- 

 velopes us in a dry or moist state, and where the rains descend 

 from it upon our land we can freely collect and use the water as 

 we please without paying tribute to any power for the privilege. 

 As to the manner in which water acts to improve when flowing 

 over land, Davy thought it was owing a good deal to the higher 

 temperature of water while standing upon or running over land, 

 that it kept plants warm during winter. This he ascertained by 

 a thermometer, placed at the bottom, near the roots, when it rose 

 ten or twelve degrees above freezing point. In general, he says, 

 " those waters which breed the best fish are the best fitted for 

 watering meadows, but most of the benefits of irrigation may be 

 derived from any kind of water." Davy stood high as an agri- 

 cultural chemist ; no man in his day stood higher ; he seems, 

 though, from his writings, never to have thorougly investigated 

 the chemical properties of river water, as respects its uses in 

 irrigation. This great man was cautious, too, in giving his opin- 

 ion on subjects chemically, which he had not well examined, es- 

 pecially if they bore any relation to his favorite one, agriculture. 

 On this account he could have had little knowledge of the value 

 of many of the impurities of river water to vegetation. Since 

 Davy's time, it has been clearly shown by the best scientific and 

 practical farmers, that the value of water depends not only on the 



