Professor Black and Mr Taylor at Cambridge.

Waikato Times, Volume XXV, Issue 2100, 22 December 1885, Page 3

Professor Black and Mr Taylor at Cambridge.

These gentlemen addressed an audience of farmcis and others in the Oddfellows' Hall, Cambridge, on Fuday evening. The audience was veiy representative, ni.my having come long distances, but it was not so large as the great impoitance of the leetmo wairanted. Major Jack-ton was called to the chair. Tlieihurman intioducrd the vi«i tors in a few appropuate lemaiks, and felt confident that those wlio had come to he.n theso gentlemen would go away with a fund of knowledge and infomiatiou which, he had no doubt, they would, after the manner of Waikato farmetH, turn to practical account. Professor Black, who, on li-mt,', was received with applause, "-nd he had h.vd the pood fortune to meet Mi McXicol when at Te Aioha, and that gentleman had thoughtfully suggested to him that a lecture, s.iv, on agucultur.il chemistry, would be \eiy acceptable to Waikato f»rmcis, who weie e\er de-mom of iinpioving their knowledgo on matters concerning the composition and producing capability of the mm]. He (the speaker) had, when in Artklaud, prevailed upon Mr Taylor to accompany him, knowing that tint gentleman had a store of knowledge, which, if properly drawn out, would be of infinite benefit and interest to farmers. Mr Taylor had readily consented, and so if they did not get out of him all they could now that they had got hold of him it was their own fault. Mr Taylor would bo very glad to give them any in for uiation about such subjects as the various kinds of nianurps now in use in England, and the various a pplicationsof these to the v arious kinds of crops, because one kind of crop re quired one kind of manure, and ho on ; and different soils leqnired diffoient manures , according to their constituents. A knowledge of theso manures would be a very mi uortant thins» for tins part of New Zealand That them should be an Agricultural Col logo for Auckland as there was fur Cantei bury with a proper teaching staff, the duties of which were to conduct classes and instruct fanners in the science of agricultuie. taking up «dcli subjects as the various kinds of hoil, and the various kinds of crops alapted to the different soils, and, also, the kind of mineral matters which the vanou* crops remov e from the earth, ought to be recognised. If they giew a ciop of wheat, for example, they would require to replace, in the m)|l that substance which you take fr>m it, or th' 1 wheat would no longer grow. The matter uf feeding stuffs was also discussed at the Cuiterbury College, and Auckland was fully entitled to an institution of that sort, whore fanners could send their Rons to ba educitod in matters of a^'iiculture in a scientific way. A seientilic knowledge alone would not make a farmci ; purhaps the most scientific man might make the worst farmer. Nor did practicil knowledge alone make the best kind of farmer. Both a scientific and a practical knowledge were necessary to bu a good fanner, and both should be combined m the one person. As to the mincial food of plant*, plant* require two kinds of minerals which the soil must furnish ; also, atmospheric food, vf lnch, as its name implies, is derived from the afmospheie. As t< atmospheric food, when a man eea a big tree 01 a crop of wheat he naturally asks what it is made of. Take a tree for example. Suppose you burn it to ashes. The weight of the ashes which remained would not amount to more than a few pounds weight. The ashes repiesented the mineral matter which the tree took from the soil, and the remainder was chit fly carbon, otherwise known as charcoal. And whero did this ome from '! The atmosphere. The charcoil in the tree was greater than everything else in it, and that was supplied by the atmosphere. And how did the tree get its charcoal ? The air we breathe contains a heavy gas called carbonic a-id gas. 10,000 gtlloin of air cont lin four gallons of c u borne acid. It did not go down to the lowest level, and form .1 layur by itself on the surface of th« ground, but penetiated away into the highest reaches of the atmoiphnro. And whero did the carbonic acid c mic from ? First of all from the breathing ot animal-'. Every breath contains 3 per cMit. of carbonic acid. Think of the number of am mils breathing caibnucacid into the atmosphere night and day ' Secondly, there wa-< the burning of hro*. When one ton of coal is burned it piodncs from two to three tons of carbonic acid, that is to say, one ton of coal pioduces from two to two and a half tons of c.ubnii acid gai>. Think of all the househ >ld hies in all parts of the globe constantly sending their c.nbonic acid into the aruvxph'jr ) ! Tim lly, they had the burning of limestone. Fonit'ily, there is underneath in the in ten >r of the oarth euonnou* deposits of Hm'xtone. Cu borne acid is generated through the action of volcanoes and centra f heat on the limestone, and the gas escapes ..thr ugh fi-suies and imnviise crevices on van ms parts of the eutVs surface. Tliero woie mx or seven tim)< more cirbmic acid gis escaping through these hssuies than from all other source-. put together. X>w a* to the effect of all this carbon on the giowth of plants. He hid gi\cn them the various sources from winch we. derive this valuable constituent, and of course if must be utilised as quickly as it c>ries forth. Supposing there were no ni3 ins of r moving it from the atmosphere, the atmosphere would become so poisonous that it would he unbreathe iblo by aiiun ils, and animal life in any form would be iui|ossible. The carbonic acid wa-s taken up by plants in the following manner The green part of living plants is all daylong drawing in carbonic gas from the atmosphere through various t-mall mouths in the inside of each leaf or blade. After the carbonic acid gas passe« into the plants it is distributed, and its functions are performed under the influence of sunlight. The lecturer then explained the relationship between plants and nnimilf, and 1101 10 gu«es necessary to the existence of etch The amount of progress mule by plants depended upon the abun Juice of their foli ige, m the foliage so to sp *ak w.is the lungs of the plaits through \vhi':h they breathed the carbon necessary to their existence. Take a blue gum seed for instance and place it underneath the surface and go away say to England for 20 years, when you cams back it would be a big tree 40ft or 50ft high with all its hnnch.'s hunting in the air foi 111 >ie carbonic acid. AH tlut big tree did not come frotu the little Meed. What took place vyas simply this. The seed b 'gins to throw its roots down into the ground, and, the cSomicil acti >n proceeding, its little leaflets soon peep ibove the surface, opening their tiny mouths and breathing in carbonic acid, and fn>m this source they dprive then growth. The big treo which you see is charcoal and watei, the constituents of all pi mtx. As to the mineral constituents of plants, supposing a treo weighing about 10 tons, is cut down on the top of a mountain where it wrill not be inteifeied with by any animal, let it remain there in the opon air for say ."tOO year- and then go and sue what remains of it, It would be found that the carbon was slightly oxydised, and that the carbonic atid gas would be whistling through the air and drawn in byootneother plants*. There would simply be found where the treo once lay a few si>ots of earthy matter. The mo«t important constituent perhaps would be phosphate of lime, of which phosphorus is the chief constituent. Then tfieie vv.w also lime, magnesia, potash and soda, Theruweie of course others, such aa silica, oxide of iron, Ac. Eveiy hundred ton* of clay soil contain as much a-, 30 per cent, of alumina. Clay did not go into plants, nor was there a particle of clay in any of us. We were in ide of anything else you like but clay, and the story tint we were only bits of clay was nothing more than a popular fallacy. The lecturer explained at con, ■iderable length and with groat olearness how this ur.portant constituent entered into the composition of the soil. Phosphate of lime was the great ittimulant of both animal and vogotable life, F/very little plant was a laboratory in itself. Evory bullock that was fattened on a piece of ground took away in his bones so much phosphate, which pa«ses into his system through the food winch ho takes. He also is a laboratory in himself. Take for instance two calves about three months old, having the same weight of bone and which have boon reared on milk. Kill one of them and burn tho bone to ashes, and say it contains one pound woight of uhouphatu of Ijine. Turn nut tho oth,or fellow fop throe years and then burn his bones to ashes, and the phosphato of lime will be found to weigh ten pounds. The atmosphere and the water (|o not contain it, therefore ho must get it from thu soil, There is, in fact, phosphate of lnno in the very milk. Plants take the phosphate from the earth, and animals from the plants, The phosphate of lnno in the soil was veiy limited, and he believed the human race were making a great mistake in Wiisting it so unnecessarily. There was in fact » terrible waste daily going on, and tho human race would sooner or later hive to take uteps to stop that waste, and devote thin v«]u«blo oowMuwt to UjQ yurpwo

for which nature intended it. In Waikato where the soil was really good, one ton weight of soil contained \ery probably contained something like one pound weight of pho.sphniu*. It was an easy calculation to ascertain haw long it would tiike to exhaust the supply. Vive bushels of whe.it contain one pound of phosphoius, theicfore a crop of .r>o. r >0 bushels would contain 10 lbs of ph<>sphoiu-<. And lOlbs of phosphorus means V>lbs of phosphate of ltme, and that means sum-thing like llOlbs of raw bone. About 1201bs of guano would furnish us with the requisite phosphato of lime for HO bushels of wheat. This> amount was rc-qui-ite so as to leave the gionnd, so far as the phosphite is concerned, in the same condition of richness as it was befoie you put your wheat in it. Unless this was donothe richest soil in New Zealand after .1 number of wheat ciops would soon dwindle to absolute bairenncss. It was not wheat alone that absoibi'd the phosphate of line, but every other ciop you put in. Look luck on tho times when Palestine and those othei Asiatic countries weie the jneat nvtions <jf the earth, say two or three thousand yeais ngo. What had become of those onro mighty nations now ? They had used up all their phosuhorns. The phosphato of lime had been extiacted from tho .soil and sent down to tho sea in the sewage of the country. Here it got absorbed by the sea plants w Inch w ero e-iton by the fishes, which weie food for tho wild vultuies of the -ea, which deposited it on the ban en l-lands and coasts of tho Pacific ocein. And England lecognising its groat value was now sending hei ships, which o\ery year brought large cargoes of this valuable minute into her ports. Palestine at one turn* was a- very tinning country, with a soil niLompaiably nch and fertile. Tin mgh it was not .so large in aiea as the valley of Waikato, still it was able to support no le-is than 300,000 fighting men. and gieat big powerful fellows they were. They w ere full of phosphate of lime. 200 lm<hpls weie prow n to the acre in those da\s on land which woiilH not now gmw anything They did not know anything about chemistry in tho-,o days, and so this wa»tc went on for somo hundieds of year,-., and Palestine now is only able to support a fewstraggling Arabs. (Continued).