1. The breathing may be exaggerated. This most often occurs in a portion of lung which is overworked on account of the inactivity of some other portion. It is also heard in emphysema in some cases. It is common in children in health.

2. Diminished breathing is noticed in consumption in the affected portions. It also occurs in some cases of emphysema.

3. The breathing may seem to be suppressed altogether in pleurisy accompanied by a considerable quantity of fluid, in pneumonia, consumption, and obstruction of the bronchial tubes.

4. Bronchial breathing is heard in parts of the chest in which it ought not to occur, in diseases in which the lung becomes solidified, as in pneumonia and consumption.

5. Peculiar sounds are produced by air passing through cavities in the lungs. They are sometimes musical in character, often resembling the sound produced by blowing into a bottle.

6. In chronic bronchitis and emphysema, sibilant or whistling and sonorous sounds often accompany respiration. These sounds are produced by contraction of the air-passages at some points.

Rales

Certain sounds known as rales are often heard in disease of the lungs, never in health. They are chiefly of four kinds, as follows: 1. Crepitant rales, a fine, dry, crackling sound, heard just at the end of inspiration, not at all in expiration, most distinct just after the patient coughs; heard in consumption, pneumonia, and pleurisy. 2. Subcrepitant rales, a fine bubbling sound, heard in both inspiration and expiration. It occurs in bronchitis, pleurisy, consumption, pneumonia, and in oedema of the lungs. 3. Mucous rales, similar to subcrepitant, but louder and coarser. Heard in pneumonia, acute and chronic bronchitis, and in consumption. 4. Gurgling rales are heard over small cavities. Sibilant and sonorous rales are mucous rales heard with sibilant and sonorous respiration.

The Voice in Disease

The natural sounds of the voice are much modified by disease. The following are a few of the most important modifications:

1. The voice, or vocal resonance, may be increased, as is usually the case in consumption and pneumonia, and sometimes in emphysema.

2. The vocal resonance is diminished when there is a slight accumulation of fluid in the chest.

3. The voice may be sup pressed entirely, as is the case where there are large collections of fluid in the chest.

4. Bronchophony, egophony, pectoriloquy, the amphoric voice and metallic tinkling, are peculiar sounds sometimes heard in the chest, each of which has its particular significance, but requires the ear of a skilled examiner to detect.

A correct idea of the position of the lungs in the chest and their relation to other organs may be obtained by reference to Fig. 301, which shows the internal organs in outline.

Fig. 301. Outline cut, showing relative position of the internal organs.

Fig. 301. Outline cut, showing relative position of the internal organs.