732 



POPULAR SCIENCE MONTHLY 



The discovpry that the bacteria of the 

 root nodules of leguminous plants pos- 

 sess the ))o\ver of absorbing the free 

 nitrogen of the atmosphere and render- 

 ing it available for the use of the plant 

 was made by Messrs. Hunter and McAl- 

 pine, according to Mr. Young, and was 

 taught by them to their students sev- 

 eral years before Hellriegel, to whom it 

 is usually ascribed, fell upon it. They 

 found that several well-defined sets of 

 bacteria were concerned in the work of 

 nitrification, and isolated and cultivated 

 the nitrous germ, but could accomplish 

 nothing with the nitric germ till they 

 used old mortar or some lime dressing 

 with it. They also found that lime 

 compounds in the surface soil served a 

 further important use by preventing the 

 soluble silicates from being taken up by 

 the roots of the plant, the lime taking 

 up those salts and forming insoluble 

 silicates which were retained in the soil 

 and did not difTuse into the plant. So 

 a non-silicated stem, or a cellulose stem, 

 was formed, which would bend before 

 the wind without breaking, while the 

 non-silicated straw was much superior 

 in value to the silicated straw. Messrs. 

 Hunter and McAlpine denied that silica 

 in the plant gave strength and solidity 

 to the stem, and pointed out that it 

 rather, like glass, made the straw brit- 

 tle. They found out, further, that large 

 quantities of carbonic acid were pro- 

 duced in the soil through the operation 

 of the ferments, and found an outlet 

 through the subsoil drains. They made 

 other discoveries which threatened to 

 render it necessary to revise the whole 

 fabric of agricultural science, and were 

 called to account by the institutions in 

 which they were teachers for their here- 

 sies. They maintained their position 

 till the opportunity came to them to 

 make tests of their theories on Lord 

 Kosebery's Dalmeny farm. Among the 

 results of the Dalmeny experiments 

 are proof of the value of a dressing of 

 ground lime in proportions not large 

 enough to kill the bacteria, emphasis 

 of the value of potash for every crop, 

 and the discovery of a remedial treat- 

 ment for the finger-and-toe pest in tur- 

 nips. " When these experiments were 

 commenced, ground lime for agricultu- 

 ral purposes had never been heard of, 

 whereas now there are at least six lime 

 works where extensive grinding plants 



are kept hard at work to supply the ever- 

 increasing demand for that substance. 

 Since the principles for the new soil sci- 

 ence have been put in successful prac- 

 tice at Dalmeny the scientific author- 

 ities, who at first had branded these 

 principles as absurd lieresies, have 

 changed their tune," and now the chem- 

 ical advisor of the Highland Society has 

 declared that he accepts the new doc- 

 trines. 



Plague Antitoxin. — In justifying 

 his belief in the elTicacy of the inocula- 

 tion treatment against the plague, Lord 

 Curzon, the Viceroy of India, said, in a 

 recent address at Poonah: "If I find, 

 as I do find, out of one hundred plague 

 seizures among uninoculated persons, 

 the average number who die is some- 

 where about seventy to eighty per cent, 

 while, in a corresponding number of seiz- 

 ures among inoculated persons, the pro- 

 portions aie entirely reversed and sev- 

 entj' to eighty per cent, if not more, are 

 saved — and these calculations have been 

 furnished from more than one respon- 

 sible quarter — I say figures of that kind 

 can not fail to carry conviction; and I 

 altogether fail to see how, in the face of 

 them, it is possible for any one to argue 

 that inociilation is not a wise and neces- 

 sary precaution." He had been person- 

 ally visiting the plague hospitals and 

 camps about the city, and had already 

 supported his advocacy of tliis treat- 

 ment by having luTuself and his party 

 inoculated at Simla with the plague an- 

 titoxin. 



Cultivation of India Rubber.^ 

 An article in the Bulletin of the Bureau 

 of American llepublics represents that 

 there are lands in Mexico and Central 

 America equally adapted to the cultiva- 

 tion of the India-rubber tree with the 

 Brazilian plantations, and having, in 

 addition, a salubrious climate. Former- 

 ly dependence for the supply of India 

 rubber was placed in the product of 

 wild trees, but with the increase in the 

 uses for it, and the consequent rise in 

 prices, capital is being invested in this 

 industry, and its profitable cultivation 

 is being largely engaged in. The trees 

 do not flourish at an elevation exceed- 

 ing five hundred feet above sea level, 

 and low land, moist but not swampy, 

 is the best. Land suitable for planting 



