RECOMMENDATORY NOTICES. 



OPINION OF GEORGE M'CLELLAN, M. D. 



Professor of the Institutes and Practice of Surgery, in the Pennsylvania 



College of Medicine. 

 MESSRS. TURNER & FISHER. 



I have examined the two first of the Series of Dr. Ruschenberger's First 

 Books of Natural History, with much attention, and take great pleasure in 

 giving my opinion in their favour. They are admirably calculated to diffuse 

 a sound knowledge of first principles in the sciences. They are axiomatic 

 in their design and character, and are constructed on the true principles oi 

 inductive philosophy. The general propositions all comprehend true minor 

 ones, and also the individual facts. They appear to me to have been drawn 

 up according to Bacon's strictest method of exclusions and rejections. I 

 have made the first of the series a text book in my private class; and have 

 found it to facilitate the business of communicating an accurate and precise 

 knowledge to the best educated among the students of medicine and surgery. 



GEORGE M'CLELLAN. 



Philadelphia, March 7. 1842. 



OPINION OF THO'S D. MUTTER, M. D., 



Professor of the Institutes and Practice of Surgery, in the Jefferson Medical 

 College, Philadelphia. 



Philadelphia, Jan. 18, 1842. 



DR. RrjSCHENBERGER. 



Dear Dr. I have carefully examined the " Second Book" of your very 

 valuable series on " Natural History," and cordially unite with many others 

 in bearing testimony to its merits. 



The study of Natural Sciences has been too much neglected in our " sys- 

 tems of education," and nothing can remedy the evil but the publications by 

 individuals whose reputations will be a sufficient guarantee to the public as 

 to the value of their labours of well arranged, lucid, and at the same time 

 scientific works upon these subjects. I need hardly say that the series now 

 under issue, possesses all the attributes of success. 



Very faithfully, yours, 



THO'S D. MUTTER. 



OPINION OF ROBERT M. BIRD, M. D. 



Professor of Materia Medica, and the Institutes of Medicine, in the Penn- 

 sylvania College of Medicine. 



Philadelphia, February 21, 1843L 

 MY DEAR DOCTOR. 



After a very careful examination of your Mammalogy, or Second Book of 

 Natural History, from the text of Edwards and Comte, it affords me pleasure 

 to bear witness to its merits. It is, like the First Book of the Series, on 

 Physiology and Animal Mechanism, extremely well adapted to the purpose 

 for which it was written, of opening to the pupils of our higher schools and 

 colleges, the great field of Natural History, and grounding them in the 

 principles of classification, while imbuing them with a love of the science 

 and the introduction of such works into our schools, cannot be otherwise 

 than favourable to the interests of education. 



Very respectfully yours, &c, 



ROBERT M. BIRD, 



W. S. W. RUSCHENBERGER, M. D. 



