360 Analysis of Scientific Books and Memoirs, 



for fear they will burst, and increase the heat gradually, until 

 the thermometer rises to 160 or 170°. If such an instrument 

 cannot be procured, you must judge by the finger ; the water 

 must not be so hot as to scald. It must be kept at that suf- 

 ficient degree of heat for half an hour ; it should not be kept 

 on any longer, nor a greater heat produced than above men- 

 tioned. During the time the bottles are increasing in heat, 

 a tea-kettle of water must be ready boiled as soon as the fruit 

 is done. As soon as the fruit is properly scalded, take the 

 bottles out of the water one at a time, and fill them within an 

 inch of the cork with the boiling water. Cork them down 

 immediately, doing it gently but very tight, by pushing the 

 cork in, for agitation will be apt to burst the bottles ; lay the 

 bottles on the side, to keep the air from escaping. You must 

 take care to let them lie on their sides until wanted, often turn- 

 ing them over, once in a week, or once in a month. — American 

 Journal of Arts and Sciences, vol. xv. p. 881. 



Art. XXII.— analysis OF SCIENTIFIC BOOKS AND ME- 

 MOIRS. 



I. — Principles of Natural Philosophy, or a new Theory of Physics, found" 

 edon Gravitation, and applied in explaining the general properties of mat- 

 ter, the phenomena oJ'Chemistry, Electricity , Galvanism, Magnetism,and 

 Electro-magnetism. By Thomas Exley, A.M. Associate of the Bris- 

 tol Philosophical and Literary Society. Lond. 1829. Pp. 510, and 

 4 Plates. 



The patient philosopher, who has spent a long life in exploring a small 

 portion of the material universe, and who considers himself nobly rewarded 

 if he has discovered a few important facts, and succeeded in referring them 

 to some general and well-established principles, stands appalled when he 

 first opens a book like the present. He turns to the department of science 

 in which he has himself laboured, to witness the solution of the difficulties 

 which have baffled him, and to obtain possession of the great secret of 

 which he has been in quest. But how great is his disappointment ! Tlie 

 theorist is not acquainted even with one of his facts ; and in place of hav- 

 ing any real knowledge of the subject, he finds him ignorant even of the 

 best established and most elementary truths. 



Hitherto the authors of universal theories have been mere pretenders W 

 science, or men of ill- constituted minds, who have neither patience nor 

 talents for calm research, and whose only object is to gain a little tempo-^ 

 r*ry notoriety by the boldness and extravagance of their viev^re ; but it 

 grieves us to observe, that this passion has been seizing the minds even of 



