No. 124.] 165 



always be traced to some error in its application. Some haH 

 applied too much, for it is very powerful, and h^ul killed their plants; 

 others applied it in ground already highly manured, its effects were 

 of course scarcely visible ; others had applied it on dry soil at a dry 

 season, when of course there were no means of its reaching the roots 

 in a proper state. Tn Peru it is always applied just previous to 

 irrigation, for it never rains on that coast. 



On the 12th of May last I sowed several hills of sweef corn in a 

 poor, exhausted, sandy soil, putting a table spoonful of guano to each 

 hill of five seeds, without any other manure. I feel sure that this 

 quantity in sowing is two-thirds too much, one teaspoonful would 

 suffice, besides which it was not sufficiently stirred up with the soil, 

 so that when the young, tender sprouts first germinated, they came 

 r.t once into contact with this most powerful manure, and weie con- 

 siderably injured, turning yellow, and several dying away. Three 

 or four however in each hill, survived and soon began to grow of a 

 dark green color. For the first three weeks I did not obsf-rve much 

 difference between these and some adjacent hills in the same soil, 

 ■which I had sown, also without manure, for the purpose of comparison* 

 when about one foot high I stirred into each hill about three teaspoons- 

 ful more guano, and watered all freely, as the weather was very dry. 

 On the 11th of July the -assels appeared, which is about a fortnight 

 earlier than usual. When fit for gathering for the table I exhibited 

 at the room of the Massachusetts Horticultural Society, the laroest 

 produce of one seed. It had three principal stems, two of which had 

 three heads each, and one two heads, in all eight heads, besides five 

 suckers, each of which showed the silk; the weight of this plant, the 

 roots being cut off, was 8^ lbs. At the same time I exhibited the best 

 produce of one seed out of the hills without guano or manure; one 

 stalk showed one head, no sucker, and weighed 1^ lbs. It is well 

 known by cultivators of this corn that under the usual cultivation it 

 seldom averages two heads to a seed. In my address before mentioned 

 the view I took of the action of tt.is manure and which I beo- leave 

 to state that I deduced theoretically from a consideration of the ana- 

 lysis of its contents, was that it would be more valuable in agriculture 

 than in horticulture, for that it was probable that it would diminish 

 the size of the flower, but that it would certainly increase the pro- 

 duce of seed. I consider the above experiment with sweet corn alone 

 as considerably fortifying these views and I will mention but one 

 other of my numerous experiments; it is purely a horticultural one 

 but further supports the same theory, which is very important to 

 agriculture. 



In February, 1842, I repotted two plants, an old woody one, and 

 a young cutting of Heliotrope, which were in soil entirely exhausted 

 and in which they had been about 12 months. The exhaustion of 

 the soil was proved by the leaves turning yellow and droppino- off as 

 fast as they appeared, as well as by the attenuated appearance' of the 

 shoots. On repotting, I merely added a teaspoonful of guano to the 

 same soil and replaced the plants in the same pots. In three months 

 they had both shot out most luxuriant branches, with many clusters 



