146 DR. WILLIAM STIRLING. 



presence gives rise to a characteristic and pronounced lesion 

 of the lungs. Just as the word '' trichinised " has been 

 applied to an animal infested with trichina, so we may apply 

 the word ^' ollula7iised'^ to an animal infested with ollulanus, 

 and we may, following the case of trichina, call the disease 

 ollulaniasis. 



On removing the lungs from the body they were found to 

 be studded with small rounded bodies about the size of a 

 pin's head, and quite visible to the naked eye. On making a 

 section of the lung it is found that these small millet-seed- 

 like bodies are distributed generally throughout the lung 

 texture, under the pleura, and in the vesicular structure of 

 these organs. They stand out as little white specks, especially 

 well in a lung whose blood-vessels have been filled with a 

 blue gelatine mass. 



Mode of preparing the lung for microscopic examination. — 

 Before removing the lungs from the body, the trachea was 

 opened and the bronchi and air- vesicles were filled with a 

 quarter per-cent. solution of chromic acid. The trachea was 

 then ligatured and the distended lungs were then placed in 

 a large quantity of a similar solution for three to four weeks 

 and then cut up into small pieces and hardened in spirit. 

 Sections were then made and examined in various ways. 



Of course, in the case of the lungs it is impossible to use 

 a mixture of paraffine as the embedding medium, for it runs 

 into and blocks up the air-vesicles. It is especially for such 

 vesicular organs that the freezing microtome is so valuable. 

 In order to freeze the lung the spirit must first be removed 

 by soaking it in water. Before embedding the lung in gum 

 in the freezing microtome, it will be found an improvement 

 to soak the piece of lung itself in a thick syrupy solution of 

 gum, a solution strongly recommended by Ranvier, and 

 which will be found very useful for many other organs, and 

 especially for those that are friable. As, however, one some- 

 times desires to make sections with the razor in the hand, 

 another method is required. For this purpose the lung, 

 after being soaked for twenty-four hours in gum, is then 

 hardened for a similar period in rectified spirit, and the 

 hardening completed by immersion for a few hours in abso- 

 lute alcohol. The spirit coagulates and hardens the gum and 

 renders the tissue quite hard and compact, so that it can be 

 easily cut with a knife. The sections are then placed in 

 water, which dissolves the gum and leaves them ready to be 

 mounted either unstained or after staining in any of the 

 ordinary ways. For a lung hardened in chromic acid log- 

 wood will be found very useful. It may be used in the 



