THE 
POPULAE SCIENCE 
EEVIEW. 
A QUAETEELY MISCELLANY OF 
ENTEETAINING AND INSTEUCTIVE AETICLES ON 
SCIENTIFIC SUBJECTS. 
EDITED BY HENRY LAWSON, M.D. 
VOLUME XII. 
LONDON: 
HOBERT HARDWICKE, 192 PICCADILLY; 
AND ALL BOOKSELLEES. 
1873. 
