2C THE MICROSCOPE IN MEDICINE. 



affords, at a very early period of consumption, definite informa- 

 tion not otherwise attainable regarding the nature of the malady ; 

 and at all times must furnish valuable aid in forming a prognosis 

 regarding the cause of the complaint." 



Sometimes we can discover the characters of certain tumours 

 by puncturing them with a fine-grooved needle, and then examin- 

 ing the fluid which exudes from them, and so finding out their 

 constituents. Thus, the booklets of the Echhiococcus may be 

 found in the fluid-contents of an hydated cyst. 



Very useful has the microscope proved in the detection of 

 crime, poison, and adulterations. Suspected blood-stains have 

 been proved to be such, partly by the presence of blood-cells and 

 partly by the development of blood-crystals, and of late by the 

 characteristic spectrum of the colouring matter of the blood by 

 the spectroscope. The microscope cannot actually distinguish 

 between the blood- cells of man and of other mammals ; but it 

 can distinguish between the circular cells of the blood of mammals 

 and the oval cells of birds or reptiles, and this character served to 

 detect an imposture in the case of a woman who pretended to 

 have ruptured a blood-vessel ; but on microscopic examination it 

 was proved that the blood was that of a fowl, by the oval cells it 

 contained. The late Frank Buckland, in his " Curiosities of 

 Natural History," mentions a case in which a murder was brought 

 home to a woman who had cut the throat of her little daughter. 

 A few hairs found on a knife were sent to an eminent micro- 

 scopist. They came back labelled "Hairs of a Squirrel," and it 

 was proved that the poor child, when murdered, had on a boa 

 made of squirrels' fur, some of the hair of wdiich had adhered to 

 the knife, and which thus formed the missing link in the chain of 

 evidence. 



In cases of poisoning, we may be helped in distinguishing the 

 characteristic crystalline forms of different salts — -as the octohe- 

 dral crystal of arsenious acid, the tetrahedron of tartar emetic, the 

 six-sided prisms of morphia, and the four-sided prisms of strychnia 

 and oxalic acid. In cases where children have eaten poisonous 

 fruits or berries, we may recognise seeds in the matter vomited ; 

 among others, those of Bdladojina, Hyoscyamus^ D^italis or 

 Fox-glove, Stramonium^ the Papaver sotnniferwn or Opium, 

 Poppy, etc. 



