132 



THE POPULAR SCIENCE MONTHLY. 



Eyesight, Good and Bad. By Robert B. 



Carter, F. R. C. S. London: Macmil- 



lan & Co. 1880. Pp. 262. Price, 



$1.50. 



It has been the object of Dr. Carter, in 

 preparing this work, to furnish such infor- 

 mation on the structure and function of the 

 eye and to give such hints on the care of 

 the eyesight as everybody should know and 

 take heed of. Experience as an ophthal- 

 mologist has shown him the need of such a 

 work, as a large portion of the time of such 

 a practitioner is, he says, "occupied, day 

 after day, in repeating to successive pa- 

 tients precepts and injunctions which ought 

 to be universally known and understood." 

 The work considers the structure of the 

 eye, the action of lenses in forming images, 

 the like action of the eye, and the various 

 ways in which these images are distorted, 

 imperfectly formed, etc., according as the 

 eye is defective. The care of the eyes, the 

 effect on them of natural and artificial illu- 

 mination, and some practical hints on spec- 

 tacles, are among the subjects treated. The 

 volume will be found valuable in every 

 household, both as a means of obtaining 

 such knowledge in regard to the eyes as it 

 is important to know and as a convenient 

 reference-book. 



The Perception of Space and Matter. By 

 Rev. Johnston Estep Walter. Boston : 

 Estes & Lauriat. 1879. Pp. 451. 



In this volume Mr. Walter has pro- 

 pounded a theory of perception differing 

 widely from any of previous writers. He 

 reviews and criticises the theories of Reid, 

 Hamilton, Bain, and Spencer, none of which 

 are to his mind satisfactory explanations of 

 the mode in which we perceive the external 

 world. He denies that the existence of such 

 a world is immediately given in conscious- 

 ness ; or that from our experience of force 

 an idea of an extended external cause can 

 arise ; or that the postulating of laws of 

 thought, constraining us to invest the exter- 

 nal world with space relations, offers a sat- 

 isfactory solution of the problem of percep- 

 tion. That which the mind knows immedi- 

 ately is only the way in which it is affected 

 and the relations between those various 

 affections. These relations are, however, 

 only relations of sequence, and there are no 



elements given in these time relations by 

 which the mind can arrive at space-rela- 

 tions. In order, therefore, that the mind 

 should be able to clothe external things 

 with space-attributes, it must have immedi- 

 ate knowledge of spatial relations among 

 its own sensations that is, mind must be 

 extended. " There must be," he says, 

 " something really capable of prompting the 

 mind to look outward. But this condition 

 is not supplied in any mysterious innate 

 laws of cause and effect or of association. 

 It is supplied in the immediate perception 

 of spatial exteriority within the sphere of 

 the mind itself or of its phenomena. . . . 

 We come to think of a cause, or causes, 

 external to and independent of the mind, 

 for the reason only that we previously have 

 had the immediate experience of the mind 

 acting as an external cause, so to speak, on 

 mind." This doctrine of mind being an en- 

 tity occupying space he regards as satisfac- 

 torily resolving the difficulties that have 

 hitherto remained irresolvable. The work 

 is original in its results, lucid in its exposi- 

 tion, and direct in its arguments, and will 

 be found a valuable and interesting discus- 

 sion of the subject. 



The Metaphysics of the School. Vol. I. 

 By Thomas Harper, S. J. London : 

 Macmillan & Co. 1879. Pp.592. Price, 



$5. 



In the reaction of modern thought 

 against the discussions and teachings of 

 the schoolmen, Mr. Harper thinks there has 

 been little or no discrimination between the 

 good and the bad, and that with some that 

 was frivolous there has been cast aside 

 much that was of value. He avows himself 

 a disciple of the scholastic doctors, and, 

 in the preface to the present volume, under- 

 takes to show that their metaphysics does 

 not deserve the unstinted reproach cast 

 upon it, either on account of its terminol- 

 ogy, or of the subjects discussed, or of the 

 manner in which the discussions were car- 

 ried on. He has, therefore, undertaken to 

 present the essential parts of the writings 

 of the scholastics, especially those of St. 

 Thomas and Saurez, in a form acceptable 

 to modern readers. The exposition will run 

 through four large volumes, of which this is 

 the first. 



