142 
Penrose and Bennett’s sliding helico- 
graph, 129. 
Permian fossils of Cultra, 53, 
Perreaux (M.) on a dynamometrie ma- 
chine for measuring the strength of 
textile fabrics and other substances, 
128: 
‘Peterhead, on some fishes, crustacea and 
mollusca found at, 78. 
Petermann (A.) on the distribution of 
animal life in the arctic regions, 112. 
Philology, on the present state of Medo- 
Persic, 90. 
Physics, 1. 
Physiology, 78. 
Pigolite of Prof. Johnston, on the analysis 
of a substance resembling the, 35. 
Pisa, climatological notes on, 110. 
Plants, morphological analogy between 
the disposition of the branches of exo- 
genous, and the venation of their leaves, 
66; on the altitudinal ranges of, in the 
N. of Ireland, 7d. 
Platinum, on the atomic weight of, 33. 
Poisson’s theoretic anticipation of magne- 
crystallic action, 20. 
Polypes, on the universality of a medu- 
soid structure in the reproductive gem- 
mez of the tubularian and sertularian, 
70; on the signification of the ovigerous 
vesicles in the hydroid, 71, 
Porter (the late G. R.) on the productive 
industry of Paris, 119. . 
Portsea, statistics of the island of, 118. 
Potassium, iodide of, 37. 
Powell (Prof.) on luminous beams, 11; 
on a peculiarity of vision, #b,; on con- 
verging sunbeams, 12, 
Pronouns, on the forms of the personal, 
of the two first persons, in the Indian, 
European, Syro-Arabic and Egyptian 
languages, 88. 
Pterotheca, new genus of, 61. 
Pumps, on some properties of whirling 
fluids, with their application in impro- 
ving the action of centrifugal, 130; for 
drawing up water by the power of a 
jet, 130, 
Punjaub, on the rocks of the Upper, 43. 
Pyrenees, on some peculiarities of granite 
in certain points of the, 62. 
Quinine, on the optical properties of a re- 
cently discovered salt of, 15. 
Railways, on the permanent way of, 122 ; 
on an improved cast-iron sleeper for, 
127, 
Rain, on four simultaneous experiments 
in the island of Bombay, to determine 
INDEX II. 
the fall of, at different heights below 
200 feet, 25; monthly amount of, from 
the register, Armagh Observatory, 29. 
Rankin (Rey, T.) on an aurora observed 
at Huggate, 31; meteorological sum- 
mary for 1851, at Huggate, 2. 
Rankine (W. J. Macquorn) on the recon- 
centration of the mechanical energy of 
the universe, 12; on the causes of the 
excess of the mean temperature of ri- 
vers above that of the atmosphere, re- 
cently observed by M. Renou, 30; on 
telegraphic communication between 
Great Britain and Ireland by the Mull 
of Cantyre, 128; on the mechanical 
process for cooling air in tropical cli- 
mates proposed by Prof. C. P, Smyth, 
ib, 
Reaping machine, model of a new, 129. 
Red-start, black, on a singular locality 
chosen for its nest by the, 71. 
Reflecting instrument for use at sea, on 
an improved form of, 12. 
Renou (M.) on the causes of the excess 
of the mean temperature of rivers above 
that of the atmosphere, as recently ob- 
served by, 30, 
Retina, on a case of vision without, 3. 
Rivers, on the causes of the excess of the 
mean temperature of, above that of the 
atmosphere, 30. 
Robinson (Rey. Dr.) on drawings to illus- 
trate recent observations on nebula, 
22. 
Robinson (R,), model of a new reaping 
machine, 129. 
Rocks, on the microscopic structure of 
certain basaltic and metamorphic, and 
the occurreice of iron in them, 34, 
Ronalds (Prof. E.) on the oil of the sun- 
fish, 39. 
Rose (C. B.) on the discovery of a new 
Talpina?, 55. 
Ross (Rear-Admiral Sir John) on the au- 
rora borealis, 31. 
Rosse (The Earl of), drawings to illustrate 
recent observations on nebula, 22. 
Rotatory forces, mechanical proof of the 
composition of, 122. 
Royle (Dr.) on the black and green teas 
of commerce, 69. . 
Ruad, on the antiquities of the island, 98. 
Sabine (Colonel), letter from Prof. Henry 
on the plan adopted for investigating 
the meteorology of North America, 
26. 
Salt, on the sources of common, 41 ; on the 
distribution of common, and other sa- 
line bodies, with a view to show their 

