HISTORICAL INVESTIGATION. 21 



bules, with a greater tendency than usual, to run together into 

 rows, like piles of coin, I remarked to him that his blood 

 assumed an inflammatory or a feverish appearance. He replied, 

 that he had been for about thirty-eight hours without sleep, 

 having sat up with a sick friend the night before, and having 

 some gastric irritation in addition, he had felt feverish all the 

 evening. Observations on pus, mucus, the urine, and the 

 various forms of malignant tumors, &c., all exhibit the value 

 of this instrument to medical science. 



In medico-legal researches the microscope has already proved 

 a valuable auxiliary. It has several times been employed to 

 ascertain the true nature of spots suspected to be blood-stains, 

 &c. ; and in cases where human life was suspended upon its 

 decision. 



In 1837, M. Ollivier was directed to ascertain whether any 

 human hair was attached to the blade of a hatchet seized in 

 the house of a person suspected of murder, and if this were 

 the case, to determine the color of the hair. With the micro- 

 scope, M. Ollivier ascertained that the filaments attached to 

 the hatchet were the hairs of an animal, and not of a human 

 being ; and this was afterwards fully proved. 



