PREFACE TO THE SECOND EDITION 



The present manual represents a second edition of the former Practical Ex- 

 ercises in Comparative Physiology and Urine Analysis. 



A separate course is now devoted to urinary examinations and the direc- 

 tions therefor are issued separately. To replace this, more experimental work 

 has been added, and the experiments in chemical physiology have been aug- 

 mented. 



It is hoped that the following experiments may be of use to the student in 

 training the power of observation ; cultivating skill and accuracy ; and empha- 

 sizing the fact that first hand knowledge is the most desirable. 



I am indebted to my assistants, past and present, for useful suggestions in 

 connection with the course. 



February, 1906. P. A. F. 



PREFACE TO THE FIRST EDITION 



This little manual has been designed, especially, to meet the needs of those 

 students who desire to become physicians or teachers of science. While not 

 intended as an exhaustive treatise, it has been the endeavor to concentrate a 

 number of useful experiments into a small compass. For a few of these experi- 

 ments a somewhat special equipment may be needed ; but the majority of them 

 may be as easily performed in a preparatory school as in a college, with a little 

 experience and ingenuity on the part of the instructor. 



It has been the aim to explain clearly the essential steps of the experiments 

 and the reasons tor them ; but, at the same time, to leave opportunities for ob- 

 servation on the part of the students themselves, and to have them record their 

 own inferences of the phenomena observed. 



In the preparation of this laboratory guide, the standard and recent books 

 and papers bearing on practical physiology have been largely drawn upon, 

 among which may be mentioned the works of Stirling, Halliburton, Waller, 

 Brunton, Foster and Langley, Gamgee, Stewart, Long, Hall, Chase and others". 



In a sense, all physiology is comparative since we are dependent upon the 

 lower forms of animal life for much of our knowledge of the function of simi- 

 lar organs and parts in the higher ; but there are differences of function in the 

 different genera of animals, correlated with differences in structure and mode of 

 life. Wherever it has been practicable, in the text, these differences have been 

 pointed out. 



August, i898. p. A. P. 



