THE MICROSCOPE IN PATHOLOGY AND MEDICINE. 245 



that various causes combine to effect the deterioration 

 of drugs. They may become infested with animalculee. 

 Leaves and roots may be eaten by insects until all vestige 

 of medicinal power is destroyed. Fungi of various kinds 

 may destroy the tissue. The uncertain action of some 

 pharmaceutical preparations may be thus accounted for. 



For the method of examination in this department, as 

 well as in medical jurisprudence, we refer to the foregoing 

 chapters, contenting ourselves here with the remark, that 

 investigations involving life or reputation should never be 

 undertaken without a thorough practical acquaintance 

 with microscopic manipulation and the microscopic sci- 

 ences. He to whom such work is intrusted, should be 

 able to exhibit and to explain to an intelligent jury what 

 he has seen and what he ought to see. 



