22 Dr. John Davy's Observations on 



caught and j)]acecl in confinement; I have notes of six. From 

 all of them either excrement was voided during life, or was found 

 in the intestine on examination after death, and of a nature similar 

 to that last mentioned, composed chiefly of lithate of ammonia. 

 No other solid substance, no crystals were observable when sub- 

 mitted to the microscope. In one, as in the instance last de- 

 scribed, on opening the abdomen some delicate tubes were seen 

 ramifying on the intestine externally. These too contained an 

 opaque whitish matter, which, from the effect of nitric acid and 

 heat, appeared to be lithic acid; but, more probably, was lithate 

 of ammonia. 



11. A yellow butterfly, in confinement, voided a little semifluid 

 brownish excrement. Seen under the microscope, diluted with 

 water, it exhibited many well formed rhomboidal plates, or low 

 prisms, as if of lithic acid, with which were intermixed minute 

 granules, as of lithate of ammonia. Acted on by nitric acid and 

 heat the purple tint was produced indicative of lithic acid. 



12. A black beetle, with suckers or cushions to its feet and 

 claws, voided a considerable quantity of fawn-colored matter, in 

 little grains about the size of mustard-seed. By the same test as 

 the preceding they were found to consist chiefly of lithate of 

 ammonia. No appearance of crystals was seen under the micro- 

 scope. 



13. A Mantis (71/. bicornis, Linn.), in confinement, yielded a 

 minute portion of excrement. This, mixed with a little water on 

 a glass support, exhibited under the microscope a few minute 

 rhomboidal crystals, and, acted on by nitric acid and heat, 

 acquired a pink tinge, denoting the presence of a little lithic 

 acid. 



14. A fire-beetle {Lampyris igniia, Linn.) voided, in confine- 

 ment, a little brownish excrement. It appeared under the micro- 

 scope to consist chiefly of epithelium-scales and of granules ; the 

 latter, of lithate of ammonia, being dissolved instantly by dilute 

 nitric acid, and acquiring when heated the color marking lithic 

 acid. 



15. A light yellow moth, during the night, in confinement, 

 voided a large quantity of excrement, that is, large in proportion 

 to the small size of the insect: it was white and semifluid. Un- 

 der the microscope it was found to abound in granules of about 

 S'S^u'U "^ '*" '"'^'' '" diameter; they were completely dissolved by 

 dilute nitric acid, and afforded on evaporation when heated the 

 rich purple hue distinctive of lithic acid. 



16. A brown moth, with white spots, weighing 1*6 grain, voided 



