470 



Lectures •» Agricultural Chemistry and Geology. By 

 James F. W. Johnston, M.A., F.R.SS. L. & E. 

 Reader in Chemistry and Mineralogy in the University 

 of Durham, &c. William Blackwood and Sons, 



Edinburgh. 

 To enable one to write usefully on the subject of these 

 Lectures, it is evident that the most intimate knowledge 

 of chemical or geological science is not all that is neces- 

 sary ; an acquaintance with the practical details of farm- 

 in" is required by any one who would apply the doctrines 

 of chemistry in the improvement of agriculture ; and 

 Professsor Johnston, in his capacity of Chemist to the 

 Agricultural Chemistry Association of Scot and, has 

 enjoyed opportunities of becoming acquainted with 

 correct agricultural management, better than perhaps 

 ever before fell to the lot of any scientific man. 1 he 

 consequence is, that while his writings will doubtless for 

 a long time to come be an authoritative standard to 

 which all questions about the bearings of chemistry on 

 agriculture will be referred, both they and his Lectures 

 have a practical and most useful tendency. 



In Scotland the efforts of Professor Johnston during 

 the past year, in diffusing a knowledge of the relations 

 of chemical science to the practice of the farmer, have 

 been extraordinarily successful. Some of the immediate 

 results of his agency on behalf of the Agricultural 

 Chemistry Association will be found in the Report in 

 another column, of the late half-yearly meeting of that 

 Society ; but perhaps as much benefit will ultimately 

 arise from the spirit which he has aroused in agricultural 



THE AGRICULTURAL GAZETTE. 



by the establishment of no fewer than seven or eight 

 agricultural periodicals in Scotland within the last year. 



We mention all these as the effects of Professor John- 

 ston's teaching in Scotland, to show the value to agri- 

 culture generally, of a systematic work on Agricultural 

 Chemistry and Geology, by one so thoroughly qualified 

 to write on these subjects. But we must also select for 

 this purpose some extracts from these Lectures. 



The following remarks are on the action of lime as 



manure : — 

 " The changes,'therefore,which lime and organic matter, 



supposed to be free from nitrogen, respectively undeigo, 



and their mutual action in the soil, may be summed up 



ai follows : — 



" 1. The organic matter, under the influence of air 



and moi.sture, spontaneously decomposes, and besides 

 carbonic acid which escapes, forms also other acid sub- 

 stances which linger in the soil. 



" 2. With these acids the quick -lime combines, and 

 either by its union with them or with carbonic acid from 

 the air, soon (comparatively) loses its caustic state. 



M 3. The production of acid substances by the oxida- 

 tion of the organic matter goes on more rapidly under 

 the disposing influence of the lime, whether caustic or 

 carbonated. These acids combine with the lime, liber- 

 ating from it, when in the state of carbonate, a slow but 

 constant current of carbonic acid, upon which plants at 

 least partly live. 



4, 4. The organic acid matter which thus unites with 

 the lime continues itself to be acted upon by the air and 

 water, aided by heat and light— itself passes through a 

 succession of stages of decomposition, at each of which 

 it gives off water or carbonic acid, retaining still its hold 

 of the lime, till at last, being wholly decomposed, it 

 leaves the lime again in the state of carbonate ready to 

 begin anew the same round of change. 



" During this series of progressive decompositions, 

 certain more soluble compounds of lime are formed, by 

 which plants are in part at least supplied with this earth, 

 and which with the aid of the rains carry off both lime 

 and organic matter from the soil. And again, the more 

 rapid the production of the acid substances which result 

 from the union of the organic matter with oxygen, the 

 more abundant in general also the production of those 

 gaseous and volatile compounds which they form by 

 uniting with hydrogen, so that, in promoting the form- 

 ation of the one class of bodies, lime also favours the 

 evolution of the other in greater abundance, and thus in 

 a double measure contributes to the exhaustion of the 

 soil. 



" The disposing action of lime to this twin form of de- 

 composition feiv varieties of organic matter can resist, 

 and hence arises the well-known efficacy of lime in re- 

 solving and rendering useful the apparently inert vege- 

 table substances that not unfrequently exist in the soil. 



" Of the Comparative Utility of Burned and Un- 

 burned Lime. — Is there no advantage, then, you may 

 ask, in using caustic or burned rather than carbonate or 

 unburned lime ? If the ultimate effects of both upon the 

 land be the same, why be at the expense of burning ? 

 Among other benefits may be enumerated the following: — 



" 1. By burning and slaking, the lime is reduced to the 

 state of an impalpable powder, finer than could be ob- 

 tained by any available method of crushing. It can in 

 consequence be diffused more uniformly through the 

 soil, and hence a smaller quantity will produce an equal 

 effect. This minute state of division also promotes in a 

 wonderful degree the chemical action of the lime. In 

 all cases chemical action takes place between exceedingly 

 minute particles of matter, and among solid substances 

 the more rapidly, the finer the powder to which they can 

 be reduced. Thus a mass of iron or lead slowly rusts or 

 tarnishes in the air; but if the mass of either metal be 

 reduced to the state of an impalpable powder — which 

 can be done by certain chemical means — it will take fire 

 when simply exposed to the air at the ordinary temper- 

 ature, and will burn till it is entirely converted into 



oxide. By mere mechanical division the apparent action 

 of the oxygen of the air upon metals is augmented and 

 hastened in this extraordinary degree, and a similar result 

 follows when lime in an impalpable state is brought into 

 contact with the vegetable matter upon which it is in- 

 tended to act. 



44 2. The effect of burned lime is more powerful and 

 more immediate than that of unburned lime in the form 

 of chalk, marl, or shell sand. Hence it sooner neutralises 

 the acids which exist in the soil, and sooner causes that 

 decomposition of vegetable matter of every kind to com- 

 mence, upon which its efficacy, in a great degree, depends. 

 Hence, when it can easily be procured, it is better fitted 

 for sour Grass or arable lands, for such as contain an 

 excess of vegetable matter, and especially for such as 

 abound in that dead or inert form of organic matter 

 which requires a stronger stimulus— the presence of 

 more powerful chemical affinities, that is— to bring it 

 into active decomposition. In such cases, the lime has 

 already done much good before it has been brought into 

 the mild state, and remaining afterwards in this state in 

 the soil, it still serves, in a great measure, the same 

 slower after-purposes, as the original addition of car- 

 bonate would have done. 



11 3. Besides, if any portion of it, after the lapse of 

 two or three years, still linger in the caustic state 

 it will continue to provoke more rapid changes among 

 the organic substances in the soil, thanmild lime alone 



could have done. 



M 4. Further, quick-lime is soluble in water, and 

 hence every shower that falls and sinks into the soil 

 carries with it a portion of lime, so long as any of it 

 remains in the caustic state. It thus reaches acid 

 matters that lie beneath the surface, and alters and 

 ameliorates even the subsoil itself. 



u 5. It is not a small additional recommendation of 

 quick-lime, that by burning it loses about 44 per cent, 

 of its weight, thus enabling nearly twice the quantity to 

 be conveyed from place to place at the same cost of 

 transport. This not only causes a direct saving of 

 money—as when the burned chalk of Antrim is carried 

 by sea to the Ayrshire coasts— but an additional saving 

 of labour also upon the farm, where the number of hands 

 and horses is often barely sufficient for the necessary 



work." 



The remark in the last paragraph of this extract from 

 Prof. Johnston's Lectures, demonstrates that attention to 

 the practical bearings of his subject, of which we have 

 been speaking, no less than the other portions of it 

 evidence his scientific ability. We shall return more than 

 once to the consideration of selections from this work, 

 which must for many years be a text-book on the subjects 

 of which it treats. 



calculation of produce, &c, is of courseHUmTteT 

 county of Ayr ; and, great as the benefits are which* 

 exhibits, how much greater would they be in a nations 

 point of view were the naturally rich lands of EneltoJ 



and Ireland subjected to a similar process ! It. BouU 



Esq., in Ayrshire Agriculturist. ' ^ ' 



Laughable Mistake — A carrier, in the neighbourhoai 

 of Bolton, recently had to convey a barrel of R ma« 

 cement to a gentleman, and a barrel of guano tot 

 farmer, each of which he delivered to the wron°- part * 

 A plasterer commenced preparing the guano, which wu 

 given to him as Roman cement ; and, after much diflu 

 culty, owing to the bad smell, he succeeded in pla9terint 

 a few yards of the gentleman's house ; but, the stench 

 becoming past his endurance, he called out to the gentle, 

 man, and said, "lam very sorry, but I must beg of too, 

 to get some other person to finish this job, for I never 

 met with such Roman cement before. I am quite sick 

 and the smell will poison me if I go on ; besides did 

 you ever see Roman cement so yellow ? " The gentle- 

 man said there must be some mistake, for it evidently 

 was not cement, and accompanied the plasterer to tbe 

 carrier's, where they found the farmer complaining about 

 the barrel of stuff he had got. It was like sand ; but 

 when mixed with water it turned into stone, and would 

 flag his field instead of making the Grass grow almost as 

 quick as winking, as he was told this new manure would do. 

 His man had mixed water with some of it, and spread it out- 

 and, on returning a short time afterwards, he found the 

 stuff as hard as a flag, and came to him in breathless 

 haste, saying, " Mestur, I nevvur seed sitch stuff i aw 

 my loife as yon, for I mixt sum on't wi weytur, un its 

 turned into a flag." — " O ! " exclaimed the plasterer, 

 M that must be the Roman cement, and I have been 

 mixing up your guano instead of it." — Bolton Free Press. 



Miscellaneous. 



Statistics of Tile-draining in Ayrshire. — Tile drain- 

 ing^as a system was commenced in this county about 

 twenty years ago. At that period a great many farmers 

 were very averse to it ; so much so, that otherwise intel- 

 ligent men would not consent to give it a fair trial. One 

 great objection regarded the durability of the tile, and 

 the improbability of the water getting down to the drain ; 

 all hesitation on these scores, if properly manufactured 

 and judiciously laid, have been completely set aside : and 

 to show how thoroughly the agricultural interest have 

 become persuaded of the immense advantage of the sys- 

 tem, it need only be stated that there are beyond fifty 

 Ti!e-works in Ayrshire alone ! These will produce on 

 an average thirty millions of tiles yearly — a quantity capa- 

 ble of draining not less than 12,396 imperial acres, 

 allowing a distance of eighteen feet between the drains, 

 and the tiles one foot long. The number of acres in 

 Ayrshire is 793,600, and suppose one fourth to be inca- 

 pable of amelioration, there will still remain 595,200 of 

 improvable land. At the present rate of tile-making, 

 taking it for granted that the whole will be used, and de- 

 ducting 150 millions as the manufacture of previous 

 years, it would require nearly 43 years to complete the 

 drainage of the county. The price of thirty millions of 

 tiles, at 25s. per 1000, would be 37,500/. The quantity 

 of coal consumed will be about 15,000 tons, and the 

 number of men and boys employed in making them r.ot 

 less than 1200. Thirty millions of tiles, one foot in 

 length, will lay 1,621,621 falls of drains, 18 J feet to the 

 fail, or nearly 6000 miles. Supposing the average cost 

 of cutting, laying, and filling the drains to be 4J. per 

 fall, the total would amount to 27,027/., and calculating 

 a labourer's wages at 10*. per week, for sixteen weeks in 

 the year, the usual period of draining in this county, it 

 follows that employment is given to 3378 men — a matter 

 of no small moment, especially at a season when other 

 out-door work is not to be had. Granting that 150,000,000 

 of tiles have been kid prior to this date, 61,980 imperial 

 acres will necessarily have been drained. Take the pro- 

 duce before the land is subjected to this process at six 

 bolls, and now at ten, per acre — a medium average — the 

 increase over former years will be 247,920 bolls, or 

 123,960 quarters. Carrying the calculation a little far- 

 ther, suppose that equal enterprise is displayed during 

 the next ten years— and there is every probability that 

 it will far exceed it, should no political shock affect the 

 encouragement of home agriculture— the stimulus given 

 to the productive capabilities of the soil will be still more 

 strikingly apparent. Ten years' draining at 12,396 acres 

 yearly, will give a total of 123,960, or an increase at the 

 previous average of 247,920 quarters of grain, thus 

 showing an augmentation iu the means of existence of 

 66 per cent., while it is well known that the gross in- 

 crease of the population in any previous period of ten 

 vears has not much exceeded 15 ncr cent. The above 



• Notices to Correspondents, 



Adhesive Land. — Villager. — You may safely use the sand, of 

 which you sent a specimen, in the manner you propoie. 

 With respect to your light land, pond mud and clay, pre- 

 viously mixed with lime, are likely to be beneficial applica- 

 tions. 



Alpaca.— E. R — Thanks for your correction ; the passage was 



quoted from another paper. The ordinary route from Pern 

 is, of course, round Cape Horn. 



Bran.— F.S.— Thank you. You will see in our Home Corres- 

 pondence that your information has been anticipated. 



Common Melilot.— A. B.— Your specimen is Trefoliom meli- 

 lotus officinalis. It is useful as food for horses, sheep, &c, 

 but is inferior in this respect to another species of tlie same 

 plant, the Sicilian Melilot, or long-rooted Clover. See Hort. 



Gram. Woburnensis. 

 Dairy Vessels.— M. <?.— We have made inquiries on the sub- 

 ject of your question, and shall soon be able to give you the 



Failure in Clover.-TF. C.-This may be remedied if the 

 weather and soil be suitable, by sowing Italian Ry e -£ ras * 

 over the bare spots immediately after harvest. It wouia oe 

 too late, we think, for Clover. 



GxASS.-Landlord.- Your specimen is Anthoxanth urn odora- 

 turn, or sweet-scented vernal Grass, of ^h.ch Mr S nclair 

 gives the following character in his Hort Gram *<*>urn- 

 Insis:-«This Grass constitutes a part of the hertoge o pas- 

 ture on almost every kind of soil, though it only ■«£«>£ 

 perfection in those that are deep and moist The chief pro 

 perty that gives merit to this Grass is its early growth IMS 

 a true permanent pasture Grass. It do esnot appear to be 

 particularly liked by cattle." The l^ter rna hw *ore 

 valuable for grazing than the first crop. It is said to give 

 new-mown hay its odour. . ».._ „- those 



Highways-Gates.-^ Constant ^ flrf ^-^f f £^ es aS w h?S 

 mentioned by our correspondent are usual y falga tes. w n 

 are so hung as to shut of themselves; and «e^ 

 persons wilfully leaving them open would be jnsvi«ao 

 damage thereby occasioned They i *Pjearto » e m ra , 

 fences of the parties by or for whom they ^^Vrough 

 ject to the easement enjoyed by the ; publi o Joassms tnr ^ 

 them, and the public must so use the right as noi 



other parties.— W. «*«-* in a south border; 



Hops.-.*. R. C.-Sow the seed in March m a sown 

 keep them for a year in the .^ed-bed, wd » en £ p ^ 

 out a foot apart. They require protection for ^tn be ^ 



ter, as they are tender when young. * ne -~L. intertwined 

 tained from a female which has been purpo £l> » We 



with a male, so that the flowers may come in con 

 have sent your note to Ruricula. „ wmnn ication on the 



SAWDUST.--Serm.-See Mr. Parke 'a ■ f£™X™^ of this 

 manufacture of peat charcoal, in aprevwu >u 

 Paper. His suggestions there may be «*«™ 1 £ > re8 t of your 

 jlphuric Acio.-Car/.-You will find that [™\ CorIc9 . 



Stj 



il nnu ui««- "■- - . nones- 

 cd amongst the Howgn o( 



letter was inserted and answered 



pondence of last week. Use acid mQnlire in U ie iw-r. -• 



water; sprinkle it over each layer of "janurM .x h t . 



the rate of 30 lbs. of acid to 5 cwt. ?f ''?"™£ r, be mixed in 

 ever quantity of litter you may consider that to 



your manure. « r riinarv purposes of 



vIlue op RooTS.-QnerW.-For the ord ma nM» Swede j 19 



feeding sheep and oxen, we consider 2fl > tons ftt the 



tons of Carrots, and 24 tons of Mangold J ««U ar . 



. period when it is best as food, to be equal in * ribas M jj. 



ticular purposes, however, they to*"}*^^^**" 

 gold Wurzel given to cows does not tamUhe'r for 



do i Carrots, again, are P ecul . ia ^ y n J rS everance in c«rtWf 

 horses. Ferns may be destroyed by Pf ; sev fstence in Gra* 

 them off as soon as they appear. Their exist 



indicates light, sandy, soft ^U navcb een received too W* 

 ***As usual, many communications have oeeu 



JWatfttts. 



HOPS, Friday, July 12. dtff w o„« 



continues free from vermin, but mould" on u.e -.^p-oW" 1 



more active, and speculator, buying t ' t,l ^ na3a> „ kS*™^*^^- 



H AY.— Per Load of 36 Trusses. 



Smithfield, July 12. . 



Prime Meadow Hay 00. to 9* | Clover - 100. to ISO. | 

 Interior ,, BO 86 I j oHW Coo***' 



to 3* 



Cumberland Market, July \U 



Soperior Old Hay 100. to 105. | Superior Clover 1 90. » }«- strt * ** » 

 NevrHay 



75 



SIN.. Clover^ J» \,. T ««»» 





Old H»y 

 N»w Bay 



80, to 08. j Old Clover "0. 1** * 

 75 80 New Clov.r « «w ■ 



Trade very duU at the »*>T« prf "' 



