YALE AGRICULTURAL LECTURES. 97 



Question Is lucerne grown on your farm ? It is difficult to 

 make it yield a good crop, and I don't consider it profitable. 



Mr. Quincy was here obliged to leave the Convention, and 

 the subject of root crops was introduced by Judge FRENCH, 

 and an animated debate held on this topic until the lecture 

 hour arrived. 



THIRTEENTH DAY. FEB. 15, 1860. 



Prof. BREWER opened his Tobacco lecture yesterday with a 

 rapid sketch of the history of the imperial weed, and referred 

 to the pains and penalties which attended its use under succes 

 sive sovereigns. The chemical composition of the plant is very 

 remarkable, and worthy of serious study by present and pros 

 pective growers. Nicotine, the deadly principle to which all 

 the ill effects of tobacco are due, is, as every one knows, a 

 deadly poison. Besides this, the plant contains a number of 

 acids, resins, and volatile oils. The strength of tobacco is 

 determined by the quantity of nicotine ; the flavor by the oils 

 and resins. The ash is of all the most important to the farmer, 

 for this is made up from his available plant food in other 

 words, from his farm capital. The oils, resins, and acids come 

 from the air, and hence cost us nothing. Take a given quantity 

 of tobacco and burn it to ashes, and we find that the proportion 

 is enormous. The roots give two to fourteen per cent, of ash, 

 the stems dried sixteen, and the leaves seventeen to twenty- 

 four per cent. As the leaves are the great bulk of the crop, 

 the robbery of the soil is correspondingly great. One thousand 

 pounds of tobacco takes an average of two hundred pounds of 

 ash ; and two thousand pounds, which may be regarded as a 

 large crop, four hundred pounds of ash. Now, a crop of wheat 

 of thirty bushels to the acre takes but thirty-six pounds of ash 



5 



