heat of an Argand lamp, using a few common 

 glass tubes as materials. Every farmer who 

 uses calcareous manures ought to have some 

 means for testing their strength, and this seems 

 to be completely within the power of all to ob- 

 tain, and to make use of, with very little atten- 

 tion. But, though the process as above de- 

 scribed is sufficiently plain to all who have the 

 slightest knowledge of the chemical properties 

 of the substances used, it may appear unintelli- 

 gible to others ; and, therefore, we hope that the 

 following explanations may be pardoned by 

 those to whom they are altogether useless. 



The principle upon which the apparatus works 

 is the same as that of the more expensive and 

 complicated apparatus of Davy, (described in 

 his Agricultural Chemistry,) which we have 

 heretofore considered the best — that is, by sepa- 

 rating and ascertaining the weight of the car- 

 bonic acid combined with the lime of the ma- 

 nure. Every hundred grains of calcareous 

 earth, or carbonate of lime, is composed always 

 of similar proportions of lime and of carbonic 

 acid — which proportions, by weight, are 56 

 parts of lime, and 44 of carbonic acid. Of 

 course, if we know how much weight is lost in 

 100 grains of earth, partly of carbonate of lime, 

 (as marl,) by driving off its carbonic acid, the 

 rule of proportion will show what was the 

 amount of carbonate of lime contained in the 

 sample of earth. 



When the muriatic acid reaches the earth in 

 the bulb, it immediately combines with the lime 

 by its greater attraction, and the weaker car- 

 bonic acid is disengaged in the form of gas, and 

 escapes into the air through the tube containing 

 the dry muriate of lime — which substance at- 

 tracts moisture so powerfully as to retain all 

 that might otherwise pass out with the gas. — 

 The same muriate of lime will serve for many 

 experiments, as by being heated in the tube its 

 dryness is restored previous to every trial. This 

 salt is formed by the combination of muriatic 

 acid with lime, and therefore every experimenter 

 may provide it for himself by filtering and eva- 

 porating the fluid left in this process of decom- 

 posing carbonate of lime. — Ed. Far. Register. 



THE SOUTHERN PLANTER. 



205 



AGRICULTURAL MACHINES, 

 Having had some experience in the construc- 

 tion of machinery for manufacturing operations, 

 and having felt the advantage resulting from its 

 use, we have labored hard to extend its benefi- 

 cial influence to the sister art of agriculture. — 

 This we have found an uphill business; but 

 this must be done ; nice mechanical implements 

 and labor-saving machines must become much 

 more common than they are, before the same 

 excellence can be obtained in the art of agri- 



culture that marks the march of intellect in 

 other professions. We are frequently told, this 

 is all true, but it is impossible to adapt ne- 

 gro labor to the use of complicated machinery. 

 This has been so often said, that it is generally 

 believed, and yet we are sure nothing is more 

 erroneous. We have seen one of the best con- 

 ducted cotton factories in this country in which 

 the operatives, nearly all negroes, work at ma- 

 chinery of the most delicate and complicated 

 construction. The superintendent even prefers 

 them, on account of the better discipline he is 

 enabled to establish, to whites. Do they under- 

 stand the operation they are guiding and super- 

 intending? Not a bit of it, either black or 

 white. There is more talent concentrated in 

 one of those moving, breathing implements, 

 than their brains could comprehend in a lifetime. 

 Had he been restricted to the production of such 

 machinery as would be comprehensible to either 

 a booby negro, or a common white laborer, the 

 spinning jenny would have slept forever in the 

 brain of Arkwright, from whom it sprung. — 

 What, then, is the machine so perfect that it 

 never gets out of order, or is it so endowed with 

 intellect that it corrects itself? Not exactly, 

 although this seems to be pretty much what 

 the farmer requires in the implements made for 

 his use. But in every well conducted manufac- 

 turing establishment, there is, or there is sup- 

 posed to be, an intelligent superintendent, who 

 understands thoroughly the principles of all the 

 machines at present employed in his line of bu- 

 siness, and readily acquires a knowledge of any 

 improvements that may be made in the same. 



We have been mortified, and almost vexed 

 sometimes, when we would be taking pains to 

 explain to a gentleman and man of education 

 what we conceived to be the beautiful principle 

 of some agricultural implement, to have him 

 tell us, that he would send his man Jim to look 

 at it, as he knew a great deal more about such 

 things than he did. Again, we are frequently 

 told, this implement, or that machine, may do 

 well enough for a northern farmer but it will 

 never do for our negroes. Now we think there 

 is a little mistake in this matter ; the proposition 

 should have been stated thus ; that implement 

 is a capital thing for a northern farmer, who 

 will teach his men how to use it, and who sees 

 in person that they take care of it, but it is not 

 worth my while to buy it, to place it, as I 

 should, in the hands of my negroes to be dis- 



