526 Recent Literature. [May, 
of the difficulty, for a difference of horizon in the same forma- 
tion at so short a distance would mean a fault, and if a fault is 
once supposed it is easier to imagine it several thousand feet in 
extent, if this will account for other phenomena such as 
absence of the Potsdam where it ought to be on the northern 
edge of the southern belt of limestones; than a few hundred feet, 
leaving this and kindred difficulties to be disposed of by separate 
hypotheses. 
That the syenite south of the South-Valley-hill is an anticlinal 
is very probable, since the whole structure of the South hill to 
the Octoraro creek is anticlinal; but that the “ Eurite” which 
occurs north of the anticlinal and south of the South Valley a 
represents the Potsdam, we think “ almost without question” 
not the case, for the reason among many others that the absence of 
the white sandon between it and the valley would need ac- 
counting fo 
The map ick accompanies the paper is quite obscure, in 
spite of the explanations in the title, and it is difficult to ascertain 
whether the section given lies in Chester or Delaware county: 
One other feature of the paper is natural pena to communica- 
tions intended for small bodies of scientific men, wh Come 
more familiar with each other’s works than with those of the | 
ne | ay | te Ee ee 
world outside. This may acount for an absolute silence as to e 
thinking and working of any soul on these very interesting n ] 
intricate questions except Professors Rogers and Lewis, Mr. a 
whose work forms the target for this last contribution, and Mr. 
Rand who shoots.!—P. F. 
ECENT D PAMPHLETS.—Truck Farming at the South, a gue to the 
eg] of era for Northern markets. By Dr. A. Oémler. New Yor nge 
Judd & Co. From the ae blisher the 
Fin 3 Causes. By Pau | hat member of the Institute. Traon bse See 
agoma edition of wA French by W. Affleck, B.D. New York, Chas 
Jamaica. Annual report of the Public Gardens and Piani for the ee 
ing red 30, 1882, By D. Morris, M.A., director. Kingsto , 1883. 
uthor 
the 
The Storage of Electricity. By H. L. Greer. New York, 1883. ha 
or. 
The Scientific Roll and Magazine of Systematized Notes. — >F. SGS 
Part 11, Aqueous Vapor. London, 1883. From the Conductor, A. Ram pe 
Art eap aY on Antistic qormi and the sciences useful to, 
By R V. Clev r, A.M., M.D. Chicago, 1883. From the author. ns 
tudy of ee poison of the Heloderma suspectum, or Gila monster. 
we Mitchell and E. T. Reichert. Phi ladelphia Medical Times, peo i 78 
Sur un Saccodon d’espéce nouvelle provenant de |’Equateur i he "From 
aap “Ext. du Bulletin de la Societe Philomathique de part, 12 an 
uthor 
nae E, Report of the Zoological Society ot Cincinnati, 1882. aa fom the 
he Selective Absorption of Solar Energy. By S. P. Langley. ** 
Pica Jour. of Science, Meith. 1883. From the author. 
: í shortly. 
1 Mr. Hall sends a reply to Mr. Rand’s criticism, which will be printed 
