128 ANNUAL REPORT OF NEW-YORK 



the ap2:>lication of this subject of intensity, it is a matter of 

 familiar experience that a season uniformly dry and hot, like 

 1854 and 1856, severely affects hardy vegetation, while one uni- 

 formly cool, like 1S16 and 1848, severely tries the health and 

 quality of all tropicals. 



b. Uniformity. — 1. Tropical climates present much uniformity, 

 in the continuance of decidedly dry, hot weather as well as 

 in the transition to the wet and cool season. 



2. Temperate and cooler climates, especially in the United 

 States of America, on the contrary, are marked by sudden tran- 

 sitions, both in the progress of the season and in the change from 

 summer to autumn. Hence it results : 



a. That, in the attempt to cultivate tropicals in a climate 

 usually presenting a hot summer, as in the United States of 

 America, the health of such plants is often severely jeopardized 

 by the occurrence of a single period of cold, wet, dark and windy 

 weather, especially if it be extended over three or four days, as 

 was the casein a remarkable change from the 11th to the 17th oi 

 July, 1846. In such cases the evil to a tropical plant results 

 from bringing the whole system of it into an unusual state of 

 moisture, chill, and deficient light, and holding it there in 

 a nearly suspended state of elaboration, until chemical law 

 overpowers vital action in a greater or lesser degree. In such 

 changes, water melons, egg plants, cucumbers, musk melons, 

 tomatoes, summer squash, peppers, beans, pumpkins and Indian 

 corn suifer, and they do so nearly in the order in which they 

 are here arranged, the first suffering most. Potatoes are also 

 injured simultaneously. 



b. A similar result is also seen when hot, damp weather (which 

 is an attribute of tropical climates,) invades a climate naturally 

 cool. In this case, hardy plants seem to suffer an engorgement of 

 their vessels and an impeded action of their air tubes, by means 

 of the close state of the atmosphere and the presence of too much 

 moisture. The result in this case, as in the preceding, is the 

 deprivation of the elaborating process, and a partial and some- 

 times perfect ascendency of chemical over vital forces. The occur- 

 rence ©f such w^eather early in the summer, frequently injures 

 wheat and other grains, and grass, while later in the summer, it 

 injures apples, plums, cabbage, turnips, walnuts, &c. A single 



