74 



HA RD WICKE'S SCIENCE- G OSSIF. 



av/ay from agricultural areas, i.e. areas where the 

 land had been under long cultivation, and had been 

 well manured ; they were not found in the prairies 

 of America, nor in the uninhabited plains of Australia 

 — they were peculiar to districts where manure had 

 been spread and organic matter had decayed. Earth- 

 worms sometimes found their way down to con- 

 sidsrable depths in the soils and subsoils, and by 

 their castings brought up vast quantities of material 

 from below to top dress the area above. Darwin 

 had shown in his interesting book on the subject 

 that sometimes a single acre of meadow land con- 

 tained i8 tons of worm castings, and it had since 

 been found that in lo tons of these worm castings 

 there was at least 80 lb. of nitrogen, which was 

 equivalent to that required by two acres of wheat. 

 Apart from this top-dressing by worms, their per- 

 forations allowed the air and rain water to find their 

 way more readily down through the soil, and in that 

 way to decompose either the surface rocks beneath, 

 or to convert the subsoils into actual soils. 



ORIGIN OF HEAVY LANDS, 



In the Eastern Counties and partly in the Midland 

 Counties the subsoils were veiy kind to the farmers. 

 By ice action during the glacial period boulder clays 

 and drift sands had been strewn over these areas. 

 The heavy lands of Suffolk and Norfolk were once 

 masses of clay — old glacial moraines, rich in all kinds 

 of rocks brought from the north and north-west of 

 England, and of Scotland, and elsewhere— rocks 

 from almost every one of the older geological forma- 

 tions which, having been ground down, formed a 

 clay matrix in which they were imbedded, and, being 

 slowly decomposed, formed subsoils than which none 

 richer could be found in the whole world. 



THE CHEMISTRY OF THE FIELDS. 



Dr. Taylor then directed attention to the action 

 of the weather on the hilly countries, showing that 

 the reason they were so unproductive was that the 

 soil was nearly all washed off the surface. He next 

 dwelt upon the colour of soils, showing that light 

 soils radiated heat, the difference meaning a great 

 deal to the warmth of the soil and the germination 

 of the crop. Then different crops require different 

 materials or kinds of mineral food. The elements 

 which were the basis of all life, animal or vegetable, 

 were six in number, viz. : carbon, oxygen, hydrogen, 

 nitrogen, sulphur, and phosphorus. All the carbon 

 which plants require, was obtained from the atmos- 

 phere ; none from the soil. Oxygen and hydrogen 

 were obtained from water, which was a chemical 

 combination of both. The difficulty of the plant was 

 to get its nitrates, potash, soda, sulphur, and phos- 

 phorus, as well as other substances, which were not 

 included in the six he had mentioned, but were 

 essential to the nourishment of particular species. 



The distinctive characters of many great groups of 

 plants depended upon the fact, that they might con- 

 tain and utilise some particular element which other 

 plants did not. He drew attention to the importance 

 of phosphorus to both animal and vegetable life, 

 particularly the higher forms. Take for instance the 

 young wheat plant. Phosphorus was to be found in 

 the stem and in the first leaves when they were shed. 

 As the plant advanced in growth the phosphorus 

 migrated upwards, until when the flowering began 

 it was drawn from every part of the plant to where 

 the flower was formed. Then came the most im- 

 portant part of the wheat plant's life, the time of 

 flowering. Every farmer knew the importance of 

 that time, and the weather which affected it. The 

 Lecturer then described the fertilisation of the wheat 

 plant, which, he explained, was effected by the wind. 

 The pollen was in the first instance contained in 

 minute bags, in such incredible numbers that every 

 acre of wheat was estimated to yield 5 lb. in weight 

 of this precious dust. On the distribution of that 

 dust depended the fertilisation of the ovule, which 

 became the seed-corn ; if the operation were carried 

 out well, there would be a good crop ; if it were not, 

 there would be so many coombs less. The full 

 amount of work might have been done in the field, 

 but if the plant had not enough phosphorus to store 

 in its pollen so as to fertilise these ovules the yield 

 of corn would be deficient. The importance of 

 phosphorus was similarly felt by other plants, and 

 yet this was the most difficult mineral for plants to 

 obtain. Phosphate of potash was essential in the 

 muscles of all animals, and there could be no good 

 grazing unless the plants contained that material. 

 Why, said Dr. Taylor, take an average size man ; 

 whatever may be his habits, he is a teetotaller in spite 

 of himself. There is under a stone weight of solid 

 mineral in the composition of his body — all the rest 

 is moisture. Of this mineral matter, over two-thirds 

 were composed of phosphate of lime. How was that 

 to be obtained unless the food he consumed contained 

 phosphate of lime ? 



MODERN SANITATION AND ITS EFFECT ON 

 AGRICULTURE. 



The Lecturer dwelt at considerable length on the 

 great change in farming operations, caused by the 

 adoption of the sewerage system for the removal of 

 soil. Much of the manure which was available for 

 agricultural purposes forty years ago was now con- 

 veyed into the rivers and seas. The consequence of 

 this was the opening of the markets for all kinds 

 of artificial manures. He showed that these arti- 

 ficial manures were only fossilised manures, the 

 remains of wild animals of the Old World, whose 

 accumulations were quite as much as the accumu- 

 lations of the farm-yard heap. He further showed 

 how soil, when rich in organic matter, might 

 contain an abundance of nitrates which were 



