32 



CONTENTS. 



depend upon each other for their exis- 

 tence. \Vater is raised from the ocean, 

 diffused through the air, and poured 

 down upon the soil, so as to be applied 

 to the purposes of life. 'J'he different 

 parts of the atmosphere are mingled to- 

 gether by winds, or changes of tempera- 

 ture, and successively brought in contact 

 with the surfice of the earth, so as to ex- 

 ert their fertilizing influence. The mod- 

 ifications of the soil and the application 

 of manures are placed within the power 

 of man as if for the ))urposc of awakening 

 his industry and calling forth his powers. 



The theory of the general operation of 

 the more compound manures may be rend- 

 ered very obvious by simple chemical 

 principles; but there is still much to be 

 discoveied with regard to the best methods 

 of rendering animal and vegetable sub- 

 stances soluble; with resjject to the pro- 

 cesses of decomposition, how tbey may 

 be accelerated, or retarded, and the means 

 of producing the greatest effect from the 

 materials employed; these subjects will 

 be attended to in the lecture on manures. 



Plants are found by analysis to consist 

 principally of cbarcoal and aeriform mat- 

 ter. They give out by distillation vol- 

 atile compounds, the elements of which 

 are pure air, inflammable air, coally matter, 

 and azote, or elastic substance, which forms 

 a great part of the atmosphere, and which 

 is incapable of supporting combustion. 

 These elements they gain either by Iheir 

 leaves from the air, or by their roots from 

 the soil. All manure from organized sub- 

 stances, contain tbe principles of veget- 

 able matter which during putrefaction are 

 rendered either soluble in water or aeri- 

 form- and in these states they are capable 



of being assimilated to the vegetable or-- 

 gans. No one principle affords the pabu-. 

 lum of vegetable life, it is neither char- . 

 coal nor hydrogen, nor azote, nor oxy- 

 gen, alone; but all of. them together in 

 various states and various combinations. 

 Organic substances as soon as they are de- 

 prived of vitality, begin to pass through 

 a series of changes which end in their 

 complete destruction, in the entire sepa- 

 ration and dissipation of liie parts. Ani- 

 mal matters are the soonest destroyed by 

 the operation of air, heat, and light. Veg- 

 etable substances yield more slowly but 

 finally obey the same laws. 



The periods of application of manures 

 from decomposing animal and vegetable 

 substances depend upon the knowledge of- 

 ihese prmciples, and I shall be able to. 

 produce some new and important facts 

 iounded upon them, which 1 trust will re- 

 move all doubt from this part of agricul- 

 tural theory. 



The chemistry of the more simple 

 manures, the manures which act in very 

 small quantities, such as gypsum, alkalies, 

 and various saline substances, has hitherto 

 been exceedingly obscure. It has been 

 generally supposed, that these materials 

 act in the vegetable economy in the same 

 manner as condiments or stimulenls in the 

 animal economy, and that they render the 

 common food more nutritive. It seems 

 however a much more probable idea, that 

 they are actuall}' a part of the true food of 

 plants, and that they supply that kind of 

 matter to the vegetable fibre which is an- 

 alagous to the bony matter in animal 

 structures. 



( To be continued.) 



eOJ\^TE.^^'TS of J%'^o. S. J^oh 1, of OnSEUl^EU *%* ElECOMin, 



Silk 'Worm and Silk Miinufacture, 17 



Coloiirinp; MMlter and Piinciples of Dying, 19 



Process of CdnverLiiij^ Heets inti> Sugar, 20 



Process of converting; Starch into Sugar, 21 



LnGrange's Mctliod, 22 



On the Sugar from 1 fitato Starch, 23 



Observations on the three preceding articles, 23 



On the most salutary remedies for Diseases in Sheep, 24 



On the Blight m Wheat, 25 



Process to make Varnishes, 26 



Description of a Vapour, Fumigation or Shower Batli, 28 



An imi>roved Machine to enable Boot and Shoemakers to work without pressure upon the breast nr 



stomach, 28 



Improvement in Montgolfier's Hydraulic Ram, 29 



Chinese Corn, . . 29 



Tomato Pits, equal to fine English Gooseberries, .'. 29 



Agricultural Chemistry, 30 



