398 



FARMERS' REGISTER. 



telligence, skill, and enterprise have affected. In 

 respect to the actual cost of producinjr silk, that 

 as yet ie by no means seiiled. Mr. Mc. Lean's ex- 

 perniient, which has come the nearest to determin- 

 ing this matter vviih exacinees, is, as I have 

 ehovvn, (tir from doing it. First, he made no allow- 

 ance ibr land, trees, rent ol' buildings, culiiva- 

 tion, and superintendence. Second, he charged 

 the man's labor and board afhall' the price, three 

 dollars per week, which it would cost wiiii us. 

 Third, he states distinctly, that his silk cost him 

 much more than two dollars a p"und, though he 

 thinks that it may be produced Ibr this sum ; that 

 is, as I understand it, the mere labor olproducing it 

 can be paid lor by that sum. in his judgment. 



ON PLOUGHING IN CROPS FOU MANURE. 



From the Tliird Report of tlie Agriculture of Massacliusetts. 



Boston, March 25, 1840. 



Dr. S. L. Dana, — Dear Sir, — Two successful 

 and experienced fiirrners, otie in Franklin and one 

 in Berkshire county, have come to the conclusion 

 that, in turning in crops by vvaj' of enriching the 

 land, more benefit is derived, that is, tlie (eriiliiy 

 of the land is more advanced by plouirhing in a 

 crop aCier it has become dried or dead, than by 

 turning it in in its greaiest luxuriance and green- 

 ness. One of them showed me the results of an 

 experiment lending to this point, which appeared 

 Bironglv 'o favor liis conclusions. A well-esta- 

 blished fact is belter than ihe most elaborate hypo- 

 thesis; and prejudices, however strong, must yield 

 to facts. 



Allow me under these circumstances, to inquire 

 whether, upon your princi|)les or philosophy of 

 vegetation, there occur to you any good reasons 

 for a result so ntuih at variance wiili popular 

 opinion. Your views in (till on this subject, will 

 add to the obliganons under which you have 

 already laid the public and your respectful friend 

 and servant, Henry Colman. 



Lowell, March 28, 1840. 



Dear Sir, — The results relerred to in your letter 

 are opposed to the comnmii opinicn. Common 

 opinion, especially in agriculture, is not always 

 founded onobservation. It isolienerprejudice, than 

 opinion ; and, when inconsistent with well kno-vn 

 (acts, has not its source in otiservation or expeiiment.' 

 The whole resolves iiselfinio this, dry plants give 

 more geine than green. This follows from the little 

 we know of the process termed " fermentation ;" I 

 use the term as commonly expressive of the spon- 

 taneous decay of vegetables. It includes the three 

 stages of vinous, acid, and putreliictive fermenta- 

 tion. These are not necessarily dependent, following^ 

 in regular prugression. They are not cause and 

 effect. Putrefaction may commence first, and it 

 issodifferent from the other two, in all its stages 

 and products, that the term "lermentation'' ought 

 never to have been applied to it. The greater 

 part of vegetables are sosceptible of putrefaction 

 only, a small number become acid at once, and a 

 still smaller number everunderoro vinous, acetous, 

 and putrefiotive fermentation. Fermentation then, 

 in its widest sense, will help us to understand how 

 dry crops may he better manures tiian <jreen. Let 

 MS glance at the principles and products of ler- 

 rnentatio'1. 



let. What vegetable substances are susceptible 



of the vinous fermentation, and what are its pro- 

 ducts? 



The juices only which contain sugar, or starchy 

 convertible first into gum and then into sugar by 

 the action of a2;oii2;eflf vegetable principles, espe- 

 cially gluten. Pure sugar never ferments. The 

 vinous lermentation must be exciied by somesub- 

 stance containing nitrogen. There are three 

 things essential to vinous fermentation, air or 

 oxygen gas, moisture in due proportion, and a 

 lemperalure never below 50° F., nor above 86'' 

 F. The products ofthis process are gases, ferment 

 or yeast, and vinous liquor. The gases are car- 

 bonic acid, and hydrogen. The yeast proceeds 

 liom a change in the organization of the gluien 

 and albumen; some late French experimenters 

 think it proceeds from a continued evoluiion of 

 inftisoriai plants, hence yeast begets yeast, like 

 sowing crops of seed. However, let us leave 

 speculation. The main fiicts are as above slated. 

 I(, then, we plough in green plants, we put them 

 in a tem|)erature favorable to the commencement 

 of vinous lermentation; we bury them lijll of sap — 

 the requisite moisture for vinous fermentation ; — 

 we cover them, whilst their saccharine principle 

 is in iis perlf!ction. Every thing favors vinous 

 fermentation. The sugar and starch of the plant 

 ft-rmenied by its gluien and albumen, are converted 

 into gases and alcohol, the former arc lost in air, 

 the last washes away or is changed to vinegar. 

 All ihat remains for the liirmer is ihe altered 

 gluten and albumen, which soon putrely and form 

 iieine. xVIl the starcii and sugar of the plant are 

 thus lost. 



2il. What vegetable substances are susceptible 

 of the acid fermentation, and what are its pro- 

 ducts? 



The substances are, first, sugar, which in certain 

 cases, becomes acid, withouf nnrierLfoing vinous 

 fermenlalion ; second, gum. The circumstances 

 essenljal to acid lernieiitalion are air, moisture, 

 and a temperature from 65° to 70*^ F. ; acetic 

 acid is itself the proper lerment of acid fermenla- 

 lion. Vinegar, as is well known, sinfTularly pro- 

 moies'the formation of vinegar in vinous liquors. 

 The products are : carbonic acid, acetic acid or 

 vinegar, and some oiher acids, especially that 

 called nanceic or zumic acid, which, if not lactic, 

 is perhaps only acetic acid, holdiriif in combination 

 some azotized sul>siance. This acid combines 

 with the alkaline and earthy ingrediems of" plants 

 and soils, and fbrms very soluble sails. Green 

 plants, ploughed in, are at once placed in a situa- 

 tion most favorable for undergoing acid fermenta- 

 tion. We sufiera loss ol a part of the carbon, 

 and in addition to the sugar and starch, we now 

 lose the gum of the plants. All these are capable 

 of producing geine, and hence in ploughing in 

 green crops, we lose a ()ortion of manure. 



3d. What are the vegetable substances suscep- 

 tible of putrefaction and what are its products? 



Wiih the exception of oils, resins, &c., every 

 organized part of every vegetable maj' putrely. 

 Tlie circumstances essential to this process, are 

 air, a temperature not below 45®, and moisture. 

 No perlecdy dry |)lant ever putrefies, nor will a 

 moist one, ifair is excluded. I have had a capital 

 .exanipleof the last, in a piece of a wliite birch 

 tree, duir up from adeplh of twenty-five feet below 

 the surface in Lowell, this winter. It must have 

 been inhumed there probably before the creatioS' 



