NA TURE 



[April 23, 



1903 



AGRICULTURAL RESEARCH IN ITALY. 

 Annali della Regia Scuola Superiore di Agricoltura di 

 Portici. 2nd series. Vol. iv. (Portici, 1903.) 



THIS well printed volume contains a series of ten 

 papers contributed by the professors of the Royal 

 Agricultural College of Italy at Portici since the 

 publication of the last report in 1898, together with a 

 general review of the work of the chemical department 

 since its foundation. 



The papers are very varied in character ; the first is 

 a statistical inquiry into the production of fruit in Italy 

 and other civilised countries ; two papers treat of a 

 fungoid disease of maize and of the olive; and of three 

 papers by Prof. Casoria the chief deals with the com- 

 position of various saline waters as compared with the 

 rocks they traverse and the deposits of tufa, &c, 

 formed from them. In some of the waters traces of 

 arsenic and nickel are recorded, with titanic acid in 

 measurable quantities. 



But the paper which is of most agricultural interest 

 is the record drawn up by Prof. Giglioli, the director, 

 of the experimental work in agricultural chemistry 

 carried out at Portici since 1S77. It includes studies 

 in the life of seeds, which were shown to retain their 

 vitality when immersed for years in alcohol or chloro- 

 form, so that oxidation, however slow, is prevented 

 and the respiratory process entirely stopped. Another 

 interesting observation was the occurrence of copper in 

 the bat's guano found in certain Calabrian caves, which 

 led to the discovery that copper is a regular con- 

 stituent and probably possesses some biological func- 

 tion in some insects, from which it passes to the bodies 

 of bats and other insectivorous animals. Experiments 

 on the introduction of plants new to Italian agriculture 

 are recorded, such as the Soja bean, the camphor laurel 

 and the Smyrna fig, over the acclimatisation of which 

 the United States Department of Agriculture has 

 spent so much care. 



The field experiments carried out at Suessola include 

 trials of various manurial substances occurring 

 naturally in Italy, such as seaweed, a phosphatic de- 

 posit from Otranto, and leucite, a mineral character- 

 istic of the Vesuvian and many of the older lavas of 

 Italy, containing at times as much as 20 per cent, of 

 potash. The dryness of the climate renders the action 

 of merely finely ground mineral manures slow and un- 

 certain, but the phosphatic deposit gave good results 

 when used first for a green crop which was afterwards 

 turned in, while the trials with leucitic earth show- 

 promise, and might give better returns if a plant were 

 chosen for experiment more sensitive to potassic 

 manuring than wheat is. 



Other investigations deal with the effects of elec- 

 tricity in stimulating crop production, with the action 

 of manganese dioxide as a constituent of manures, and 

 particularly with the cultivation of wheat, the im- 

 portant series of experiments on which have before 

 been noticed in these columns. The author claims 

 that, as at Rothamsted, the plots at Suessola 

 " demonstrate that a large production of cereals can 

 continue indefinitely provided the land be well culti- 

 vated and manured. But while at Rothamsted the 

 NO. 174 7, VOL. 67] 



growth of wheat alone is possible in each year, in the 

 ' Campania Felice ' in the same year crops of wheat 

 and maize forage can be raised. Thus, by the in- 

 tensity of its production of grain, the fourteen years 

 of experiment at Suessola are equivalent to twenty- 

 eight years in England." 



While the above list is by no means exhaustive, it will 

 serve to show the activity of the experimental station 

 at Portici, and the many-sided interests of its director, 

 Prof. Giglioli. A. D. H. 



OUR BOOK SHELF. 



La Telegrafia senza Filo. By Augusto Righi and 



Bernardo Dessau. Pp. vii + 518; wth 259 woodcuts. 



(Bologna : Nicola Zanichelli, 1903.) 

 Prof. Righi has considerable claims to be regarded 

 as the father of practical wireless telegraphy. It was 

 from him that Marconi, as a student at Bologna, de- 

 rived the knowledge of modern electricity which has 

 enabled him to cross the gap which separates the Old 

 World from the New. The benefits that the university 

 and its professor have conferred on mankind by train- 

 ing a Marconi suggest the question : Should not uni- 

 versities be endowed with exceptional scholarships to 

 assist exceptional men ? The advantages of expend- 

 ing 100/. annually to help on students of average 

 mediocrity are well known. On the other hand if a 

 university should produce a man with the enterprise 

 of Marconi once in 100 years, the advantage to the 

 community of enabling him to carry on his experi- 

 ments with the accumulated amount of an annuity 

 that had been left unawarded during the interval can- 

 not be overestimated. 



A work on wireless telegraphy, coming from the 

 physical department of the University of Bologna, and 

 bearing Prof. Righi 's name, will be read with great 

 interest. The present volume is, however, rather of 

 the nature of a popular treatise intended for readers 

 not starting with any previous knowledge about elec- 

 tricity. Hence the first part, extending: over about 

 no pages, is taken up with a general account of the 

 principles of electricity and magnetism. The second 

 part deals with electromagnetic waves, the electro- 

 magnetic theorv of light, and coherers. In the third 

 we have an account of all the different methods of 

 telegraphy, from the earliest attempts at making a 

 telegraphic current flow across a river by conduction, 

 down to a close examination of the Marconi system and 

 the various inventions which have been proposed or 

 patented on parallel lines. In the preparation of this 

 part the authors have evidently made a careful study, 

 not only of the published literature of the subject, but 

 also of the patent specifications both of the " Wireless 

 Telegraphy and Signal Company " and of other in- 

 ventors, the object evidently being to give an unbiased 

 account of what Marconi actually discovered, and what 

 he derived from other workers in the same field. The 

 fourth part deals with the systems of wireless telegraphy 

 and telephony depending on the use either of ordinary 

 light or ultra-violet rays combined with a photo-voltaic 

 receiver. In a brief appendix, M. Dessau deals with 

 the recent experiments in long distance " Marconi- 

 graphy," and gives illustrations of the Poldhu station 

 and the arrangement of the antenna? on ships. This 

 appendix contains several statements of interest con- 

 cerning the rflcct of solar radiation on the transmission 

 of signals, the relative merits of the coherer and the 

 magnetic detector (the latter being considered superior 

 by Solari), and such matters. 



While the book has been specially drawn up for the 

 general reader, there are few physicists who can read 



