NA TURE 



169 



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THURSDAY, DECEMBER 25, 1902. 



AGRICULTURAL SCIENCE IN ITALY. 



Chimica Agraria, Campestre e Silvano. Di Italo Giglioli. 



Pp. xviii + 877 ; with 31 figures in the text. (Naples : 



Marghieri, 1902.) 

 HIS book, the work of the well-known professor of 

 agricultural chemistry in the College at Portici, 

 was originally projected as a treatise on agricultural 

 chemistry, to be followed by other volumes dealing with 

 fermentation and animal chemistry. Written, as the 

 author tells us, with many interruptions, between 1884 and 

 the current year, it remains but a fragment of the original 

 scheme, for it deals only with the relations of the plant to 

 water and to solar light and heat — questions, indeed, of 

 fundamental importance to the agriculture of a semi-arid 

 country like Italy. With nearly 900 pages devoted to so 

 small a section of the subject, it will easily be imagined 

 how vast is the scale upon which the work was planned, 

 and this arouses a question which struck us repeatedly 

 during the perusal of the book. Given a treatise on a 

 technical branch of science, like agricultural chemistry, 

 how far should the author deem it his duty to enter into 

 a complete discussion of whatever branch of the pure 

 science he may require to use for the explanation of some 

 technical problem ? For example, we have in the book 

 before us some ten pages, 628-638, given up to an acconnt 

 of the nature of exothermic and endothermic chemical 

 reactions. Now, though it is impossible to understand 

 the problems presented by carbon assimilation under the 

 action of light without possessing the conception of the 

 transfer of energy accompanying a reaction and the 

 reversibility of the change, we hold that the reader of a 

 book like the present will have either reached already the 

 required knowledge of pure chemistry or else must be 

 introduced to the new idea in a much less academic 

 fashion. In the main, a book of this type is written for 

 the expert and should stick very close to its text, taking 

 something more than the elements of the pure sciences 

 for granted. 



But it is precisely in this direction that Prof. 

 Giglioli's weakness lies, with the result that the book is 

 cumbered and inordinately expanded with irrelevant 

 matter, interesting enough, but not really bearing upon 

 the point. For example, all kinds of light waves and 

 ethereal radiations doubtless possess some action upon 

 the living plant, but as these effects are still practically 

 unknown, it is surely superfluous to devote fifty pages to 

 a purely text-book account of phosphorescence and 

 kindred phenomena, including the incandescent properties 

 of the rare earths in the Auer lamp, Crookes's tubes, 

 radiant matter and kathode rays ; nor, again, in another 

 section, can we see the appropriateness of a discussion of 

 the skin vision of animals or of Prof. Poulton's experiments 

 on the influence of coloured lights upon the larvre of 

 Pieris. 



This is the most unsatisfactory portion of the book, 

 and we cannot help feeling that, in his desire to be 

 exhaustive, Prof. Giglioli has discharged upon us pell- 

 mell all the references he has accumulated, without con- 

 sidering how far they have yet been made to bear upon 

 NO. 1730, VOL. 67] 



his subject. It is true that the man of science who wants 

 to go beneath the surface of things must carry in his 

 mind all sorts of cognate facts and investigations, in 

 the hope that some day they may supply a missing link 

 in his own work, but he should not present the public 

 with this raw material. 



The earlier sections of the book, dealing with the rela- 

 tions of the plant to water, are less academic, and con- 

 tain many interesting references to the author's own 

 experiences of agriculture under the hot suns and small 

 precipitation of Italy. He discusses at some length 

 the development of the root, and refers to this cause 

 the increased power of resisting drought which certain 

 manures, particularly nitrate of soda, give to the crop. 

 In this section, Prof. Giglioli draws freely on the results 

 of the Rothamsted experiments, particularly on Lawes 

 and Gilbert's paper upon the drought of 1870 and its 

 effect upon the variously manured grass plots. This 

 question of the action of manures upon root development 

 is worthy of more study than it has hitherto received, for 

 it seems to afford a clue to the explanation of the greater 

 ease with which a plant manured with nitrate of soda will 

 in some cases obtain its other mineral food from the soil, 

 as compared with one receiving the same amount of 

 nitrogen in the form of ammonium salts. 



The earlier chapters of the book have not been brought 

 so closely up to date as the later pages ; in the account 

 of the amount of water transpired by plants, we have 

 Lawes and Gilbert's figures, but not the later work of 

 Hellriegel, Wollny, and King of Wisconsin, and again, 

 in the discussion of the value of tillage in conserving 

 soil moisture, no mention is made of the valuable obser- 

 vations which have been accumulated in America on this 

 point. 



The reader who is interested in the effect of climate 

 upon crop production will find that Prof. Giglioli deals 

 repeatedly with this most intricate problem. The alteration 

 by climate of English varieties of wheat introduced into 

 Italy is discussed on pp. 187 and 379, a subject of interest 

 at the present time, when efforts are being made to get into 

 English wheats something of the " strong " character of 

 those imported from more arid countries, and again, on 

 p. 189, we have a correlation of the hay crops grown at 

 Rothamsted under various systems of manuring with the 

 rainfall of the months of April, May and June. 



On p. 100, we have a reference to Frank's discovery of 

 mycorhiza, but we have no account of the weighty 

 generalisations contained in the later papers of Frank 

 and of Stahl, which have shown how interesting and 

 widespread a variant of the general course of nutrition 

 is presented by plants with mycorhiza. 



The special value of the book lies in its enthusiasm 

 and breadth of view ; we feel we are dealing, not only with a 

 specialist, but also with one who possesses a many-sided 

 knowledge and experience. To an Englishman, it is 

 pleasant to see how references to English work abound ; 

 particularly it is clear that Prof. Giglioli has kept himself 

 familiar with the experiments at Rothamsted, where so 

 much of the pioneer work in agricultural science has 

 been done. Prof. Giglioli contrasts Italy unfavourably in 

 the matter of agricultural experiments, but will the English 

 work play so large a part in any treatise of a foreign 

 professor fifty years hence? Rothamsted stands where 



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