1864. 



THE ILLINOIS FAKMER. 



137 



npon the surface of the earth, even ia hot weather, 

 decomposition no longer goes on so rapidly as when 

 the same manures are kept in a heap, and the am- 

 monia that is produced is gradually carried into 

 the soil by rains. The other soluable substance, 

 as potash, lime, the phosphates, etc., are, of course 

 not lost, because they are not volatile. 



Nor are these soluable and valuable substances 

 lost to plants by being carried into the soil before 

 they are needed by growing plants. It has been 

 conclusively shown by eminent scientific athoritiep. 

 that any good soil, containing a fair proportion of 

 clay and carbon is capable of taking up and effect- 

 ually absorbing ammonia, lime, potash, soda, etc., 

 in a soluble form, so that little, if any, passes off 

 in the underdrainage water of such soils. These 

 substances, it is true, may wash from the surface, 

 but they cannot pass through a good soil and go off 

 into the drainage water. 



By surface manuring we mulch the ground and 

 render it cooler in summer and warmer in winter. 

 Mere shade is an important element in culture, so 

 important that many writers have thought shade 

 alone to be equivalent to manure. A piece of soil 

 heavily shaded by surface manuring actually de- 

 composes like a manure heap ; that is it undergoes 

 a sort of putrefaction or chemical change, which 

 sets free its chemical constituents, unlocks, as it 

 were, its locked up manurial treasures, and fits its 

 natural elements to become the food of plants 

 Darkeness, moisture and air are the conditions re- 

 quired for vegetable and mineral decomposition. 

 These conditions are produced in the soil by sur- 

 face manuring. 



Then, again, when the surface manure decom- 

 poses, its elements are washed into the soil, in a 

 state of solution precisely fitted to meet the wants 

 of plants, and they become themselves active 

 agents in promoting further decomposition and 

 chemicals changes in the entire body of the soil. 



Manure, then, I say, chiefly upon the surface. 

 Do not wast your manures by mixing them deeply 

 with the soil. Plant shallow. Keep roots of all 

 trees, plants, and vines, as near the surface as pos- 

 sible. There are weighty reasons for the position 

 assumed in the last sentence, which I have not 

 space now to enumerate. I say again plant shal- 

 low. Let your soil be deep and dry, but plant 

 near the surface. To farmers I would say, manure 

 upon the surface as much as possible. Top-dress 

 your grass, after mowing in July or August, under 

 a burning summer sun ; top-dress in the fall, before 

 and during the autumn rains ; manure the surface 

 while the snow is on the ground, while the March 

 winds blow, and while the April rains fall. Manure 

 your grass, instead of your corn and wheat, broad- 

 cast, at any time when you have manure and lei- 

 sure, and I will guarrntee that you will be abun- 

 dantly satisfied with the result. 



To fruit-growers I would say, do not fill your 

 8oil with manure before you plant trees, grape 

 vines, etc. Plant in good natural soil, and manure 

 from the surface, spring and fall, liberally and 

 properly, and I will guarantee you success far 

 greater than if you plant in holes and trenches filled 

 with manure, as the custom is, Surface manuring 

 and mulching are the true doctrines. I am sure of 

 it. 



Cane Juice Evoporators. 



In our last No. we offered some remarks upon 

 cane mills, referring to a few general principles of 

 universal application, which are always to be con- 

 sidered in connection with the subject. We now 

 propose in the same manner to treat of evapora- 

 tors and evaporation. But we are met at the very 

 threshhold of the subject with a difiBculty. We 

 shall not be able probably to name a single general 

 principle that is not a controverted point. Mill- 

 ing cane is a purely mechanical operation, and cane 

 mill may be estimated by fixed and acknowldged 

 mechanical standards, but evaporating juice is 

 quite a different thing, and there may be and are 

 almost as many notions and theories about it as 

 there are operators engaged in the business. We 

 may perhaps timidly remark that rapid boiling 

 with a shallow stratum of juice, is generally ac- 

 cepted in preference to slow, prolonged boiling, 

 with a heavy volume ; but this is the only general 

 proposition we would venture to make with any 

 hope of its being even complacently entertained. 

 We must, however, write something upon the sub- 

 ject, be the consequences what they may. It is im- 

 possible to tell what particular sect of evaporator 

 men we shall most offend, and as they are all about 

 alike voluble belligerent, we do not know that we 

 have any choice as to which shall take it upon 

 himself to return and overwhelm us. 



EVAPORATING BY STKAM. 



Water in its natural state, is a crystalline solid. 

 When combined, as the ancient philosophers term- 

 ed it, with a certain quantity of caloric, it becomes 

 fluid. When combined with a certain additional 

 quantity of caloric it becomes gaseous. The quan- 

 tity of caloric necessary to produce these changes 

 is always and under all circumstaces the same. 

 The temperature of ice is 32 " ; by the addition of 

 as much heat as would raise an equal weight of 

 to 174 ° , that is, by the addition of 142 =" of heat, 

 the ice becomes converted to water ; but the sen- 

 sible temperature of the latter remains the same aa 

 the ice, 32 ° , all the heat absorbed being rendered 

 Latent. If heat be now applied to water from a 

 continuous and regular source, its temperature will 

 be gradually raised to 212°, or the boiling point 

 of water under atmospheric pressure. At this 

 stage the temperature of the water ceases to rise, 

 and steam appears ; but the sensible temperature of 

 the steam will be found to be the same as the boil- 

 ing water, 212 ° . If the time which was occupied 

 in raising the temperature of the water from the 

 freezing point, 32 ° , to the boiling point, 212 ° , 

 that is, in communicating 180 ° of heat to the 

 water, be carefully noted, and the same uniform 

 application of heat be continued, it will be found 

 that at the end of exactly five and a half mesures 

 of the time the water will have entirely disappeared 

 in the form of the steam ; the steam, however, as 

 above stated, is of the same sensible temperature 

 as the boiling water, 212 ° , all the heat communi- 

 cated, say 180 mul. by 6i=S90°, having been 

 rendered, as in the case of the melted ice, laienL 

 By this we see that it requires as much heat to 

 convert a given weight of ice to water without 

 raising its temperature as is required to raise the 

 same weight of water from the freezing point, 32 ® 

 to l*?*® , that is, 142 ° ; also, that it requires five 

 and a half times as much heat to convert a given 



