20 ENCYCLOPEDIA BRITVNNICA. PRINCIPAL SUBJECTS. 



VOLUME XVIII. 

 PLAYFAIR (JOHN). By Lord Jeffrey. 



PNEUMATICS. By Sir John Robison, late Professor of Natural 

 Philosophy in the University of Edinburgh. 



POETRY. By George Moir, Advocate. Revised by TV. Edmon- 



stoune Aytoun, Professor of Rhetoric and Belles Lettres in the University of 



Edinburgh. 



POISON. By Robert Christison, M.D., Professor of Materia 



Medica in the University of Edinburgh. 



POLAND. By James Brown, LL D. Revised. 



POLAR REGIONS. By Sir John Richardson, KB. 



POLICE and POST-OFFICE. By Edward Edwards, Author 



of the article " Libraries." 



POLITICAL ECONOMY AND PRECIOUS METALS. By J. 

 R. M'Culloch. 



POLYNESIA. By the Rev. W. Ellis, Author of the Article 



" Madagascar." 



POOR-LAWS. By George Coode, Barrister-at-Law. 



POPE. By Thomas de Qoincey. 



POPULATION. By the Rev. T. R. Malthus, late Professor of 

 Political Economy, East India College, Hertford. 



POTTERY and PORCELAIN. By Chakles Tomi.inson. 



PRECESSION and PROBABILITY. By Thomas Galloway, 



late Secretary to the Royal Astronomical Society. 



PRESBYTERIANISM. By the Rev. William II. Goold, D.D. 



PRESCOTT. By William Stirling, M.P. 



PRINTING. By T. C. Hansard, Barrister-at-Law. 



PRISON DISCIPLINE. By John Hill Burton. 



PRUSSIA. By Dr. G. Von Bunsen. 



PUNJAB. By E. B. Eastwick, Author of the article " Persia.* 1 



QUAKERS. By William Howitt, Author of " Visits to Remark- 

 able Places," etc. 



QUESNAY. By J. R. M'Culloch. 



QUINTILIANUS. By Frederic W. Farrar, Fellow of Trinity 



College, Cambridge. 



RABELAIS. By Theodore Martin. 



RAILWAYS. By D. K. Clark, Author of " Mechanical Engineer- 

 ing of Railways," etc. etc. 



REGISTRATION. By James T. IIammack, Superintendent General 

 Register Office. 



