THE SOUTHEEN PLANTER. 



G65 



nia in the spring, you must have Tioticed tlie 

 rusty appearaiice of the sap (particularly I 

 think of the sn,o;ar-map,]e) oozing from the 

 stumps of trees felled not h)ng before, and cov- 

 ering the tops and sides of the stumps. Of the 

 same colour, you knov^^ is the newly extrava- 

 sated sap oa the stalks of Mdieat and other 

 grain wdien struck by the mildevs\ 



You have seen many statements by American 

 (and I believe British) agriculturists, of v\'heat 

 being reaped v-diile the grain was soft and mil- 

 ky, and the plants still green, or greenish ; 

 ■which nevertheless produced, if not a full sized, 

 yet a tolerably plump kernel, and yielded a 

 very fine and uncommonly white flour. It has 

 been as often said by the agriculturists, that by 

 such early reaping of grain, on the first appear- 

 ance of mildew, you may obtain a valuable if 

 not an abundant crop ; the sap in the stalks 

 continuing in its natural course to the heads . 

 whereas if the same grain remained uncut, the 

 seed would be shrivelled, and often give chaff 

 only instead of flour. How is this to be ac- 

 counted for? The answer which has occurred 

 to me, and which I will now state, while it fur- 

 nishes an explanation of the declared fact, 

 goes to confirm the theory of my countryman, 

 in tlie paper enclosed. It is this. 



The stalks of grain being severed from their 

 roots, the source of the malady is cut off. The 

 vessels of the stjilks are no longer distended by 

 a superabundance of sap ascending from the 

 heated soil — they cease to receive any. The 

 bursted vessels, through the wide breaches in 

 which the sap, in its rapid ascent, was rushing, 

 naturally close ; and the sap already received 

 into the stalks (further aided'perhaps by dews) 

 pursues its gentle course to the heads, and fills 

 the grain. 



The writer's remark, that grain in old fields 

 which have often been dunged, is frequently 

 mildewed, while that on new land escapes (for 

 which, on his hypothesis, he assigns a natural 

 reason,) comes in support of your opinion, that 

 long and nevv dung is injurious to grain crops. 

 I promised to give you an account of my experi- 

 ments in cultivating the common field-peas, 

 Bcme twent}- years ago at Wyoming, in which 

 they were entirely free from bugs, but this I 

 must postpone for the present, 



I am, dear sir, faithfully yours, 



Timothy Pickering. 



Iiichard Peters, Esq. 



[From a Boston newspaper, printed March 176S.] 



Some Thoughts Upon Mildews. — As the 

 public arc now, on all sides, calling upon 

 every one to communicate his oljservations upon 

 anything which, relates to agriculture; perceiv- 

 ing in reading M. Duhamers husbandry, that 

 there are a great variety of opinions, about 

 the nature and cause of mildews upon grain, 

 even among the most celebrated gentlemen 

 farmers of Europe; and desirous, if possible, 



to contribute my mite towards any useful dis- 

 covery, I have^-ventured to show my opinion, 

 founded on such observations as fully satisfy 

 myself, as it appears to me perfectly to corres- 

 pond with /ac/i' ; and in a natural and easy 

 way to account for every appearance and effect 

 of that disorder in grain. 



My fixed opinion then is and long has been 

 [in which I since find I agree with the famous 

 M. Chateau Vieux,] that the powder which 

 forms the rust, called viildews, is the extrava- 

 sated juice of plants dried by the sun, upon the 

 stalk. 



i My reasons are these: — 1st. The graip, we 

 J see, receives no more nourishment after it is 

 violently struck. 2d. On a careful inspection, 

 it appears that some of these rusty blisters are 

 actually under the outer coat or skin of the 

 stalk, and do not appear to have any communi- 

 cation from without, others a're only split in the 

 middle, some more and some less, and the rust 

 appears on the outside more or less according 

 to the opening. 3d. The learned Mr. Tillet, 

 (Duhamel tells us) with a good microscope, ac- 

 tually saw the juice issuing from these small 

 openings, over which he still perceived some 

 pieces of the membrane which imperfectly 

 covered them. This, methinks, must give ocu- 

 lar demonstration. But the two former satis- 

 fied me, the second especially appeared demon- 

 strative. 



The true cause of this extravasation is next 

 to be encjuired into. This no writer that I 

 know of has hinted. I take it to be this: a sud- 

 den obstruction of the juices of the plant, by a 

 very cool night, after several clays and nights of 

 very warm weather. 



By a continued heat, the earth is warmed to 

 a great degree, and all nature invigorated ; this 

 (!ccasi(jns a great assent of the juices, so that 

 every vessel is full (as in an animal of a ple- 

 thoric habit when all know there is most dan- 

 ger of the vessels bursting,) a sudden cold even- 

 ing at this critical season chills the tender 

 stalk, and most where it is slenderest, and these 

 brings on a stagnation. 



But the earth being deeply warmed by the 

 long and intense heat, not cooling so soon as 

 the stalk, continues the violent ascent of the 

 juices as before ; and if there be an obstruction 

 or stoppage above, in the slenderest part of the 

 stalk, w^hat must, what can be the consequence 

 of this but an extravasation, or that the vessels 

 burst? 



That in fact mildews in New England always 

 come in cool nights, after intense and continued 

 heats, I am sure from near forty years observa- 

 tion, and 'from these symptoms I have often 

 known a mildew prognosticated by observing 

 persons, in the evening preceding. Such a 

 cold, succeeding heat, every philosopher, and 

 almost every man knows, will occasion a great 

 dew. And this no doubt is the reason why 

 tills rust has been ascribed to the dew and call- 

 ed rneldeio or mildew. Whereas, I suppose, it 



