1817.) Account of a remarkable Fossil. 343 
not exceed 0:02 grain in weight. The nitric acid solution being 
supersaturated with ammonia, let fall a white precipitate, which 
was phosphate of lime, and weighed, after being exposed to a red 
heat, 1:9 gr. When this phosphate was digested in potash ley it 
assumed a yellowish-red colour, indicating the presence of a little 
phosphate of iron. The potash ley being separated by the filter, 
and mixed with sal-ammoniac, a very slight opalescence took place, 
indicating the presence of a perceptible quantity of alumina. 
The nitric acid solution, being mixed with bicarbonate of potash, 
let fall a quantity of carbonate of lime, which weighed, when dried, 
0°57 gr. Thus the constituents of the portion of scale examined 
were as follows :— 
Animal matter and moisture ....-.-++e++--- 0°33 
Phosphate of lime, with trace of phosphate of 
WONsBNG BUDD «5.2.00, 9f2.alerre o's ep pare epsin nD 
Carbonate of lime .......-. OT RE Sie, 5 0°57 
BM is g'ahs ial sine deo gysh nod « obk * ae a ss | 
Tapad . ha's usle oraleg's nd ao 
Or, in the hundred parts, 
Mi) GNAUECE s,s o.¢ biainert aise odes h 1Kuat 
Phosphate of lime .........- f ditte ae anes SOL OE 
Carponnte de Ide , ifs. «ec sieiedis ust Aa. ves le AO 
BAERS cos can de os oviaae eek ewe aie CHO ae 
100-00 
This analysis is sufficient to show us that the scales are composed 
of animal matter. They bear a considerable resemblance to bone 
in their composition, but they contain a greater proportion of car- 
bonate of lime. Perhaps the quantity of carbonate of lime which 
I state is rather above the truth ; for the quantity of it was so small 
that I could not venture, without exposing it to too great a loss, to 
dry it in ared heat. It was merely dried upon the filter, and its 
weight estimated by carefully rubbing it off the filter, and deter- 
mining the loss of weight which the filter sustained. But as car- 
bonate of lime contains no water of crystallization, and the filter 
had been exposed for some hours toa heat considerably above 100°, 
I do not think that any inaccuracy could have crept in from my 
mode of determining the weight of the carbonate of lime. My 
original experiments were destined to be made upon 15 gr. of the 
scales ; but this portion was lost from an accident; and I was un- 
willing to destroy the specimen by detaching any more of the 
scales. Hence the reason of the small scales upon which my ana~ 
lysis was made; but as I took considerable pains, I consider the 
preceding result as pretty near the truth. 
Fig. 2 exhibits a side view of the fossil, in order to show a set of 
