THE BILE. 209 



examined within fifteen minutes after the animal was killed and the gall- 

 bladder taken out of the abdomen. 



The two other absorption bands of bile are exceedingly faint in com- 

 parison with the first, and much less constant in their occurrence. One 

 of them, very dim and ill-defined, is situated at the junction of the orange 

 and yellow, immediately to the left of the line D, occupying about the 

 last third of the space between C and D. The remaining band is much 

 narrower than either of the others, but a little more distinctly defined 

 than the second. It is situated at about one-third the distance between 

 D and E. The last two absorption bands are more frequently visible in 

 sheep's bile than in that of other animals ; but all three may be some- 

 times seen in a watery solution of desiccated ox-bile which has been 

 kept, in the form of a dry powder, for several years. 



Lastly, the spectrum of bile exhibits a remarkable diminution in 

 intensity of the orange and yellow colors. As the second absorption 

 band is situated at the junction of these colors, it will account for a 

 part of this diminution; but the light of the spectrum is also remark- 

 ably dim in the space between the second and third absorption bands, ^ 

 where, in the normal spectrum, it is at the brightest. This is the 

 place naturally occupied by pure yellow, but in the great majority of 

 cases, in the spectrum of bile, there is no pure yellow perceptible, and 

 but little or no orange. The situation of these two colors is encroached 

 upon by the red and green respectively ; and in not a few instances, as 

 the spectrum terminates before the commencement of the blue, the only 

 colors really perceptible in it are red and green^ The line C in the 

 normal spectrum is situated at the junction of the red and orange, and 

 yet the principal absorption band at this point, when viewed in the 

 spectrum of bile, nearly always appears to be situated entirely in the 

 red, owing to this color taking the place of the orange on the right of 

 the line C. This peculiarity in the spectrum of bile shows itself, whether 

 the color of the specimen be greenish or yellowish-brown. 



If a tolerably thick layer of bile be placed before the spectroscope, 

 and the slit of the instrument gradually opened, the first light which 

 appears in the spectrum is a green light, in the latter half of the space 

 between D and E. On continuing to increase the size of the opening, 

 if the bile be deeply colored, the next to appear is a red light, at the 

 extreme end of the spectrum between A and B ; in less concentrated 

 specimens the red light may show itself simultaneously on both sides of 

 the absorption band at C. Afterward the green light extends further 

 toward the left until the spectrum is complete. 



The spectrum of bile, in its most important feature, namely, the ab- 

 sorption band at C, presents a remarkable similarity to that of chloro- 

 phylle. The band at C is identical in the two spectra so far as regards 

 its position and general appearance ; the only perceptible difference 

 being that in an alcoholic solution of chlorophylle its edges are more 

 sharply defined than is usually the case in the spectrum of bile. In 

 other respects, however, the spectrum of chlorophylle differs from that 



