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NATURE 
[Dec. 1, 1870 

metalliferous, and the southern and littoral provinces 
agricultural. The latter term must, however, be accepted | 
with some qualification, inasmuch as the cereals hitherto 
produced have been very scanty, and to this day the 
Republic is an importer of flour. In truth, the natural 
pasture is so abundant, and alfalfa or lucerne thrives so 
luxuriantly, that stock-farming is practised almost to the 
exclusion of all other branches of agriculture. 
Major Rickard remarks that mining in La Plata is at 
once in its infancy and in its old age. An instance of 
this anomalous state of things may be seen in Mendoza, 
where the ancient silver mines, El Rosario and San Ru- 
maldo, which were discovered as early as 1638, are again 
in active operation. The old miners dealt merely or 
chiefly with what Spaniards term “warm metals” 
(metales calidos), that is, those which could be reduced 
directly by means of mercury, and this, therefore, left for 
a later generation the “cold metal” (metal frio) which 
required for its reduction the process of smelting. Silver 
mines are not by any means confined to the province 
of Mendoza. In San Juan (where civil war and revolu- 
tion have long been fatal barriers to all industrial pro- 
gress) the district of Tontal, on the slopes of the great 
Andine range, is peculiarly rich in argentiferous lodes ; 
ordinary samples from the Mine Senor containing not 
less than 160 ounces to the ton, and first class samples 
yielding 400 ounces. But, in the opinion of Major 
Rickard, the silver mines of Famatina, in the more 
northerly province of La Rioja, are the richest in the 
whole country. That the difficulties in working them are 
formidable may be gathered from the fact that some 
are situated 13,000 feet above the sea-level, and that the 
whole district is deficient in fuel of any sort, and exposed 

during three months of the year to a rainfall so heavy as | 
to compel the miners to suspend their labours. 
province of Catamarca copper is the predominant metal, 
and in union with it an appreciable percentage of gold 
and silver has been found. During the year 1868 the 
Restauradora mine produced 2,639 tons of ore, containing | 
by assay 506 tons of fine copper; but it must be re- 
membered that the prevailing systems of smelting are 
by no means perfect. 
More than one auriferous district exists within the 
limits of the Republic, and those which are respectively 
named Gualilan and Guachi (from Gwa, which in the 
Huerpe tongue signifies gold) have for many years enjoyed 
considerable celebrity. Both of them largely enriched 
their first workers, and there can be little doubt that 
thousands of tons of ore still exist in the old workings 
which have been abandoned, partly from natural difficul- 
ties, but principally from the want of skilled labour. 
As to the other productions of the Republic, it is im- 
possible in this brief notice of a copious volume to do 
more than mention them by name. Mendoza and San 
Juan possess silver-lead mines of considerable extent ; and 
in the former province petroleum springs have been 
recently discovered. In Santiago del Estero large tracts 
of land are covered with indigenous indigo; rice and 
tobacco are cultivated in Tucuman, and in the most 
northerly provinces of Salta and Jujuy are thriving 
plantations of coffee. 
After making every allowance for Major Rickard’s | 
natural enthusiasm, it must be admitted that the country | 
| 
In the | 
whose resources he has so minutely described, offers many 
and great inducements tothe British emigrant to give 
it a fair trial. President Sarmiento desires especially to 
attract a further immigration of our fellow countrymen, 
for he infers from the success they have already achieved 
in the cultivation of the Pampas, that their energy 
and enterprise will be invaluable in developing the 
mineral resources of the Republic, and that Anglo-Saxon 
coolness and perseverance will form a favourable counter- 
poise to the opposite characteristics of the Hispano- 
American race, C. J. ROBINSON 


OUR BOOK SHELF 
An Elementary Course of Hydrostatics and Sound. By 
Richard Wormell, M.A., B.Sc. Feap. 8vo, pp. viii. and 
146. (London: Groombridge and Sons, 1870.) 
THIS little book is “designed for the use of schools, 
colleges, and candidates for University and other exami- 
nations.” In such a work it would of course be out of the 
question to look for novelty of matter: by the nature of 
the case, to praise the author’s originality would be to cast 
a doubt on his accuracy; and, while inaccuracy would 
be inexcusable, no merit can be claimed for its opposite. 
Hence, in trying to form an estimate of a book like this, 
we are inevitably led to consider whether the subjects 
treated are arranged in a simple and natural order ; 
whether the exposition of principles is clear and logical, 
the really fundamental matters being kept constantly and 
prominently before the student’s mind, and special conse- 
quences and applications grouped about them in such a 
manner as to show distinctly their mutual connection and 
dependence : whether, in short, the book is scientific in 
treatmént as well as in subject. We are sorry to say that, 
in these respects, our judgment of the work before us is 
by no means favourable. We should expect a student, 
instead of acquiring from it ideas which are capable of 
growth and expansion within his own mind, and being led 
towards the conception of the organic connection of all 
scientific truth, to conclude that science—or at least 
hydrostatics and acoustics—consists of a series of proposi- 
tions which it is his duty to “ get up” and write out on the 
first opportunity in answer to examination-questions. The 
least satisfactory parts of the book are the explanatory and 
descriptive portions, and especially the twenty-two pages 
at the end devoted to sound. The author says in the 
| preface that “the whole contains all that is required on 
these subjects [hydrostatics and sound] for the B.A. and 
B.Sc. degrees of the University of London.” If this is 
true as regards the latter subject, it is more to the discredit 
of the University than to the credit of his book. 
Studien tiber das Central Nerven-System der Wirbel- 
thiere. Von Dr. Ludwig Stieda, Prosec:or in Dorpat. 
(Lendon: Williams & Norgate.) 
Dr. Lupwic StTrepA is already well-known for his 
admirable papers on the central nervous system of 
osseous fishes, birds, and some mammals. The present 
work embraces a description of the central nervous 
system of the frog, rabbit, dog, cat, mole, and mouse ; 
an account of the course of the fibres in the spinal cord 
of Vertebrata generally ; a comparison of the brain of the 
various classes of Vertebrata with that of man, and finally, 
a comparison of the cerebral with the spinal nerves. Of 
the description of the brain and spinal cord of the several 
mammals mentioned above we need say nothing here, 
except to remark that the account is full and carefully 
drawn up; the minutest structure of the several parts 
being given as well as their coarser anatomical features. 
In regard to the brain of the frog, the parts of which 
have received such different names, Dr. Stieda gives the 
following description of the organ as it appears when 

