IV PREFACE. 



interesting set of experiments on urinary and gouty calculi ; but 

 they were made and published before the method of analyzing 

 animal substances had been thought off. The same remark ap- 

 plies to Mr Hatchett's experiments on shells, bone, zoophytes, 

 and membrane. They contain many important facts which have 

 been overlooked by modern chemists ; but at the time of the pub- 

 lication of these experiments, namely, 1799 and 1800, it was 

 not to be expected that any attempt at ultimate analysis could 

 be made. 



The modern chemists to whom we are indebted for the most 

 important analyses of animal substances, hitherto laid before the 

 public, are Mulder and Scherer. The results of their investiga- 

 tions will be seen in the following work. By laying the pre- 

 sent state of our knowledge before the reader, it is to be hoped 

 that British chemists, when aware of the vast quantity of inves- 

 tigations yet requisite to place Animal on the same footing as 

 Vegetable Chemistry, and when medical men become sensible 

 that the farther improvement and final perfection of physiology 

 will depend upon an accurate knowledge of the constituents and 

 properties of animal substances, the subject will speedily draw 

 general attention, which alone is wanting to insure a rapid 

 advance. 



