Mr Edwards on Chanige qf Colour intlie Cfiamekon. 315 



in various ways, and might, in turn, reflect different rays, in 

 the same way as very slender plates of the metals produce a 

 succession of colours, according as their thickness is increased 

 or diminished. 



Now, regarding all these explanations, it must at once be 

 seen, that they could be regarded in no other light than mere 

 hypotheses ; and the subject appeared to me so curious as to 

 demand a more complete solution. I accordingly anxiously 

 availed myself of the opportunity which was presented me by 

 M. Savart, of examining anew these changes of colour, and 

 of making researches as to the causes of so singular an occur- 

 rence. 



About the month of June 1833, Mr Savart received two cha- 

 meleons from Algiers, which he preserved alive till towards the 

 end of October. One of these reptiles, M'hich we shall desig- 

 nate No. 1. was usually of a purplish grey colour ; but during 

 the night, when it was in profound sleep, it appeared of a whit- 

 ish-grey ; and occasionally it exhibited along its sides, spots of 

 a dirty yellow hue, aud sometimes there appeared on different 

 parts of its body, other spots which were red, or even of a deep 

 violet colour. Finally, some days previous to its death, it had 

 assumed a yellowish hue, and was covered with small black 

 miliary points, which by degrees extended, so as to form con- 

 tinuous spots, and to cover almost the whole body. 



The chameleon No. 2. was usually of a deep bottle-green 

 colour, approximating to black. When it was sound asleep, it 

 became like the other of a pale dirty yellow ; and, during the 

 course of the day, there was often observed upon its sides, spots 

 of a lettuce-green colour, while the rest of the body was of a 

 bottle-green shade. When it was placed near to the window, 

 and a hope of escaping seemed to be excited, the tinge of let- 

 tuce-green extended itself over the whole body. Finally, when 

 it sickened, some yellowish spots appeared; but it maintained 

 till death the general colour of azure-green, which was habitual 

 to .it. 



Ij'j-IThe chameleon No. 2. changed colour more easily than the 

 other ; but in both, these changes were effected only gradual- 

 ly. Besides, we can distinctly state, that they were entirely in- 

 dependent of any distention more or less considerable of the 



