468 DEPOSITION OF SALTS. 
Salts deposited by Water of Irrigation. 
The attentive traveller in Egypt and Nubia cannot fail to 
notice many localities, generally of small extent, where the soil 
is rendered infertile by an excess of saline matter in its com- 
position. In many cases, perhaps in all, these barren spots lie 
rather above the level usually flooded by the inundations of the 
Nile, and yet they exhibit traces of former cultivation. Obser- 
vations in India suggest a possible explanation of this fact. A 
saline efflorescence called “Reh” and “ Kuller” is gradually 
invading many of the most fertile districts of Northern and 
Western India, and changing them into sterile deserts. It con- 
sists principally of sulphate of soda (Glauber’s salts), with 
varying proportions of common salt. These salts (which in 
small quantities are favorable to fertility of soil) are said to be 
the gradual result of concentration by evaporation of river and 
canal waters, which contain them in very minute quantities, 
January, 1869, the deaths from malarious fever in the Canavese district— 
which is asserted to have been altogether free from this disease before the recent 
introduction of rice-culture—between the 1st of January and the 15th of Octo- 
ber, 1868, were two thousand two hundred and fifty. The extent of the injurious 
influence of this very lucrative branch of rural industry in Italy is contested 
by the rice-growers. But see Szeconpo Laura, Le Risaje, Torino, 1869; 
Semi, J] Miasina Palustre, p. 89; and especially CARLO Livt, Della coltiva- 
zione del Riso in Italia, in the Nuova Antologia for July, 1871, p. 599 et sega. 
According to official statistics, the rice-grounds of Italy, including the islands; 
amounted in 1866 to 450,000 acres. Jt is an interesting fact in relation to 
geographical and climatic conditions, that while little rice is cultivated sowth of 
N. L. 44° in Italy, little is grown in the United States north of 35°. To the 
southward of the great alluvial plain of the Po, the surface is in general too 
much broken to admit of the formation of level fields of much extent, and 
where the ground is suitable, the supply of water is often insufficient. 
The Moors introduced the cultivation of rice into Spain at an early period of 
their dominion in that country. The Spaniards sowed rice in Lombardy and 
in the Neapolitan territory in the 16th century; but besides the want of water 
and of level ground convenient for irrigation, rice-husbandry has proved so 
much more pestilential in Southern than in Northern Italy that it has long 
been discouraged by the Neapolitan government. 
