1839.] On Isinglass in Polynemus sele, Buck. 207 



anterior part of the upper jaw, behind which a small detached group of 

 palatine teeth are placed on the vomer. 



The liver consists of an elongated left lobe and a short right one, un- 

 der which the gall bladder is situated. The stomach is a short mus- 

 cular cul-de-sac, both orifices of which being placed at the anterior 

 extremity, from which numerous small cecce are given off, the intestine 

 extends straight to the vent ; in all these respects it corresponds 

 nearly with P. paradiseus. The air vessel, which is quite absent in 

 the latter, and on which the peculiar value of this species seems to 

 depend, is a large spindle-shaped organ about half the length of the 

 fish, thick in the middle and tapering toward the extremities, where it 

 ends in front by two, and behind by a single tendenous cord ; similar 

 small tendenous attachments, about twenty-two in number, connect it on 

 either side to the upper and lateral parts of the abdominal cavity. 

 This organ, which is called the sound, is to be removed, opened, and stript 

 of a thin vascular membrane which covers it both within and without, 

 washed perhaps with lime water and exposed to the sun, when it 

 will soon become dry and hard ; it may require some further preparation 

 to deprive it of its fishy smell, after which it may be drawn into shreds 

 for the purpose of rendering it the more easily soluble. The fish which I 

 examined weighed about two pounds and yielded about sixty-five grains 

 of Isinglass, not quite pure, but containing about 10 per cent, of 

 albumenous matter, owing perhaps to the individual from which it was 

 taken being young and out of season, and not above a tenth part of the 

 ordinary size of the species. But the solution after having been 

 strained appeared to be equal to that of the best Isinglass, which costs in 

 Calcutta from twelve to sixteen rupees a pound. As the subject thus 

 seemed to be of consequence, I gave a portion of the substance in 

 question to Dr. O'Shaughnessy for its chemical examination. 



a. Breadth of the back, 



b. Scale magnified, 



c. Scale from lateral line magnified, 



d. Air vessel or sound natural size. 



Calcutta, 2>rd May, 1839. 



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