1882.J 



THE LANCASTER FARMER. 



as flo hams, and bolh should be carefully 

 smoked. The ini'servative priiiciitle of sm .ke 

 is known as oreosoto. iSinokc made by burn- 

 ing corn-cobs is liighly esteemed, but those 

 eniraged in curing meats on a large scale 

 prefer the smoke obtained from dry hickory 

 that has been stripped of its bark. The 

 smoking process must not be too much hur- 

 ried or the creosote will not have time to 

 penetrate the entire substance of the meat. 

 Ten days' smoking is usually sullicient, unless 

 the pieces are very large and tliick. 



A process in liam-curing practiced by some 

 of the h'ading packini,'-houses consists in 

 creating the smoke in au oven outside of the 

 smoke-house and passed through underground 

 pipes into it. The smoke, rising from the 

 tloor to the top of the house, encounters two 

 opposite currents of air drawn from the out- 

 side. These currents cause the smoke to form 

 into a rapidly revolving horizontal column 

 which passes among the hams. The smoke 

 is not warm, and there is no heat to melt the 

 hams or hot air to blacken them. The hams 

 under this process are smoked in very much 

 h'ss lime than by the old method. 



While canvassing hams has nothing to do 

 with their flavor, it is a protection from in- 

 sects, and will pay the farmer for the extra 

 hibor. It should be done before warm 

 weather. Wrap each ham in coarse brown 

 paper and then sew it up in cotton cloth cut to 

 suit the size, following the shape of the ham. 

 "When covered as described, dip them in a 

 wash made of lime-water and colored with 

 yellow ochre. Hang up in a cool place to dry. 

 The wash closes the interstices of the muslin, 

 and the whole forms a perfect protection 

 against insects. The room in which any kind 

 of cured meat is stored should be dry and 

 cool, and the darker the better. 



THE PART WHICH WORMS PLAV IN 

 NATURE. 



The latest fruit of Charles Darwin's labors 

 in the field of physical research is presented 

 in a volume treating of The Formation of Veij- 

 elttblc Mould TIaowjh the Action of Worms. 

 The term vegetable mould is commonly ap- 

 plied to that superficial layer of soil, generally 

 of a blackish color and a few inches in thick- 

 ness, which covers the whole surface of the 

 land in every moderately humid country. 

 The uniform fineness of the particles of 

 whii'h it is composed is one of its chief char- 

 acleristic features, and this may be well ob- 

 served in any recently ploughed field, wliere the 

 top layer is exposed on the sides of a furrow. 

 It is the object of this book to show that the 

 fine earth composing this superlicial layer has 

 been brought up to tlu' surface by worms in 

 the form of castings or e.\erement. We are 

 thus led to conclude that all the so-called veg- 

 table mould which is strewn over the smface 

 of the ground has i)assed many times through 

 the intestinal canals of worms, and hence the 

 the term "animal mould" would be in some 

 respects more appropriate than the term in 

 common use. 



Some of the conclusions reached in this 

 volume were suggested in a paper published 

 by Mr. Darwin many years ago, Jjut many 

 scientists rejected his conclusions with respect 

 to the part played by worms in the formation 

 of the mould, on account of their assumed in- 



capacity to do so much work. This seems to 

 have been an instance of that inability to 

 sum up the effects of a continually recurrent 

 cause which has often retarded the progress of 

 science. In order to meet the objection raised, 

 Mr. Darwin resolved to make more observa- 

 tions of the same kind as those previously 

 published, and to attack the problem on 

 another side l)y weighing all the castings 

 thrown up within a given time in a meas- 

 ured space, as well as by ascertaining 

 the rate at which objects left on the sur- 

 face are buried by worms. It appears that 

 near Macr Hall, in Staffordshire, (piick lime 

 bad been spread, about the year 1827, thickly 

 over a field of good pasture land which bad 

 not since been ploughed. Some square holes 

 were dug in this field in the begiiming of Oc- 

 tober, tS37, and the sections showed a layer 

 of turf fin-med by the matted roots of the 

 grasses, half an inch in thickness, beneath 

 which, at a depth of three inches from the 

 .surface (the 2^ inches intervening being vege- 

 table mould), a layer of the lime in powder or 

 in small lumps could be distinctly seen run- 

 ning all round the vertical *ides of the holes. 

 Coal cinders had been spread over a part of 

 this same field in the year 1834, and when the 

 holes mentioned were dug— that is, after an 

 interval of three years— the cinders formed a 

 line of l)Uick spots round the holes at a depth 

 of one inch beneath the surface, parallel to 

 and above the white layer of lime, Over an- 

 other part of this field cinders had been strewn 

 only about half a year before, and these either 

 lay on the surface or were entangled among 

 the roots of the grasses. Here Mr. Darwin 

 saw the commencement of the burying pro- 

 cess, for worm castings bad been heaped on 

 several of the smaller' fragments. After an 

 interval of 43 years this field was re-examined 

 and now the two layers of lime and cinders 

 were found almost everywhere at a greater 

 depth than before by nearly one inch. It fol- 

 lows that mould to an average thickness of 

 one-fifth of an inch had beenannually brought 

 up by the worms and spread over the surface 

 of the field. Mr. Darwin cites a number of 

 instances in which lu^ was able to compute 

 the rate of mould formation by worms, which 

 of course, must vary according to the nature 

 of the subsoils. The rate, for example, must 

 become very much slower after a bed of mould 

 several inches in thickness has been formed ; 

 for the worms then live chicfiy near the surface 

 and burrow down to a greater depth so as to 

 bring up fresh earth from below only during 

 the winter, when the weather is very cold, or 

 during midsunnner, when the earth is very 

 dry. Of course, too, relatively few 

 worms would be found in stony ground, 

 and their production of mould would 

 be comparatively slow. The effect, 

 however, of their action, even in 

 such cases, is astonishing when extended pe- 

 riods of tin\e are considered, as the following 

 example shows. We are told that a field near 

 Mr. Darwin's liouse was last ploughed in 1841, 

 then harrowed, and left to become i)a,sture 

 land. For several years it was clothed with 

 an extremely scant vegetation, and was so 

 thickly covered witli small and large dints 

 (some of them half as large as a child's head,) 

 that it came to be known as "the stony field." 

 Mr. Darwin says he can remember doubting 



whether ho should live to see these larger 

 flints covered with vegetable mould and turf. 

 But the smaller stones disappeared before 

 many years bad elapsed, as did every one of 

 the larger ones after time ; so that after thirty 

 years a horse could gallop over the compact 

 turf from one end of the field to the ether and 

 not strike a single stone with his shoes. This 

 was certaiidy the work of worms, for though 

 castings were not frequent for several years, 

 yet some were thrown up month after month, 

 and these gradually increased in numbers as 

 the pasture improved. Still more striking 

 was the burying of a path paved with flag- 

 stones, whieh in 1843 ranacro.ss Mr. Darwin's 

 farm. The worms threw up many castings 

 in the interstices of these stones, and al- 

 though during several years the path was 

 weeded and swept, yet ultimately the weeds 

 and worms prevailed, the path became covered 

 up, and after several years no trace of it was 

 left. On removing in 1877 the thin over- 

 laying layer of turf, the small flagstones, all in 

 their proper places, were found covered by an 

 inch of fine mould. It will surprise most 

 readers to learn how large an amount of 

 mould may be formed by worms on the sur- 

 face of a field in a single year. Mr. Darwin 

 calculates that the castings ejected annually 

 by each earthworm weigh, on an average, 

 more than twenty ounces. It has been esti- 

 mated by other observers that 53,707 worms 

 exist in an acre of land ; but this estimate is 

 based on the number found in gardens. As- 

 suming that only half the number named, or 

 about 27,U0() worms to the acre, live on 

 pasture land, and that each worm annually 

 ejects twenty ounces, we should have fifteen 

 tons as the weight of the castings annually 

 thrown up on an acre of land, and helping to 

 form the layer of vegetable mould. 

 Arehseologists are probably not aware how 

 I much they owe to worms for the preservation 

 of many ancient objects ; coins, gold orna- 

 ments, stone implements, etc., if dropped on 

 the surface of the ground will infallibly be 

 buried by the castings of worms in a few 

 years, and will thus be safely preserved. For 

 instance, some years ago a grass field not far 

 from Shrewsbury was ploughed up, and a sur- 

 prising number of iron arrow heads were 

 found at the bottom of the fiUTOws, which 

 no doubt had been left strewn on the battle- 

 field of Shrewsbury in the year J403. In 

 Abiugcr, Surrey, on a trench being dug in 

 1870, the concrete floor of the atrium or re- 

 ception room belonging to a Roman villa was 

 disclosed at a depth of two or two and one- 

 half feet. At first sight it appeared impossi- 

 ble that the vegetable mound covering the 

 pavement couid have been brought ui) by 

 worms, but upon close inspection the con- 

 crete was found decayed and completely per- 

 meated with worm burrows. Through these 

 channels in the softened mortar the worms 

 have been throwing up their castings from 

 the ground beneath, and heaping on the con- 

 crete pavement a layer of fine earth, during 

 many centiu'ies and perhaps for a thousand 

 years. The coins discovered in this place 

 dated from 133 to 37.) A. D. The pavement 

 of Beaulieu Abbey in Hampshire now lies at 

 a depth of from 0] to 11^ inches beneath the 

 surrounding turf-covered surface. A part of 

 this pavement has been uncovered, but re- 



