EXAMINATION OF ANIMAL FLUIDS. 685 



membrane of the mouth. The debris of various articles taken 

 as food are also often found in the saliva, rendering its study 

 more difficult to the unpractised eye. 



Sputum. To examine sputum it should first be placed in water, 

 in order that any dense cretaceous or tubercular portions may be 

 deposited at the bottom of the vessel, and thus separated from 

 the lighter portions, which, on account of the confined air, will 

 generally float upon the surface. The different constituent ele- 

 ments may then be isolated by breaking up small detached 

 masses with a glass rod, and spreading them out upon a glass 

 slide. Parts presenting any peculiar appearances, as dark spots, 

 fibrous tissue, &c., should be removed by means of broad-pointed 

 forceps and scissors, and examined separately and with much 

 care. 



The various matters which enter into the composition of 

 sputum, and which complicate its study, are thus enumerated by 

 Prof. Bennett. 



" 1st. All the tissues which enter into the composition of the 

 lung, such as filamentous tissue, young and old epithelial cells, 

 blood-corpuscles, &c. ' 2d. Mucus from the oesophagus, fauces, 

 or mouth. 3d. Morbid growths, such as pus, pyoid and granular 

 cells, tubercle-corpuscles, granules and amorphous molecular 

 matter, pigmentary deposits of various forms, and parasitic vege- 

 tations, which are occasionally found in the lining membrane of 

 tubercular cavities. 4th. All the elements that enter into the 

 composition of the food, whether animal or vegetable, which 

 hang about the mouth or teeth, and which are often mingled 

 with the sputum, such as pieces of bone or cartilage, muscular 

 fasciculi, portions of esculent vegetables, as turnips, carrots, cab- 

 bages, &c. ; or of grain, as barley, tapioca, sago, &c. ; or of bread 

 and cakes ; or of fruit, as grapes, apples, oranges, &c." It has 

 lately been asserted by Shroeder Van der Kolk, that fragments 

 of pulmonary tissue may be detected in the sputum before the 

 existence of ulceration can be revealed by physical exploration. 

 This, however, is doubted by Prof. Bennett. 



A very common appearance in sputum under the microscope is 

 represented by small masses of molecular and granular matter. 



In the sputum of phthisis small lumps of softened tubercle 

 may often be found, mingled with purulent mucus, at the bottom 

 of the vessel. They have a yellowish, cheesy appearance, and 

 consist of small and somewhat transparent cells, round, oval, or 

 triangular, in shape, and varying from the l-120th to the l-75th 

 of a millimetre in their longest diameter. They are known as 

 tubercle-corpuscles, contain a number of granules, and are sur- 

 rounded by free granular matter and oil-globules. (Fig. 400.) 



In the sputum which accompanies the cretaceous or calcareous 

 transformation of tubercle in the lungs, small, hard or gritty, 

 and white masses will be found, consisting of amorphous aggre- 

 gations of phosphate and carbonate of lime mixed with some 



