Analysis of the Cojprolites of Birds. 55 



riate is therefore too high. The very small portion on which I 

 have operated, has rendered the amount so solved impossible to 

 estimate. But disregarding that, I find the coprolite yields to 

 water as follows: — the first 15 grains being the experiment 

 made with your first parcel, where yellow drops formed round 

 the edge of the dish. I have not observed this in two subse- 

 quent trials, but only a yellow cast here and there in the crust. 

 As this first trial yielded a much greater proportion to water than 

 either of the others, I conclude that water and sulphate of lime 

 are quite unequally distributed, even in the same sample. After 

 several digestions in cold alcohol, 



Grs. Per cent. 



The first 15 grs. gave to boiling water, 0-30 = 2-0000 



Per cent. 



Second 30 grs. gave to cold water, 0-1545=0-5150 ) n.q^^o 



And then afterwards, to boihng do. •1288 = 0-4293 i 



Third 20 grs. gave to cold do. -1545=0-7725 ) i .jgio 



And then afterwards, to boiling do. •0777=0-3888 i 



3)4-1056 



1-3685 

 the average solved by water. 



If we now assume that taken up by cold water to be only 

 urates, and that by boiling, sulphate of lime, setting its urate 

 against the sulphate dissolved by cold, we have in 30 and 20 

 grains 5150 + 07725 --=1-2875 or 06437 percent. Supposing 

 this 6437 to exist as urate of ammonia, y\ in round numbers 

 would consist of that base, leaving for uric acid per cent. 0-5794 

 grains. You will observe therefore how much of the little you 

 have been able to spare, has been used in quantitative examina- 

 tions. My stock of coprolite had now reduced itself to the 20 

 grains last mentioned, and I felt desirous of ascertaining from 

 the amount of precipitated urate of silver, the exact quantity of 

 uric acid, and of making a more rigid quantitative examination 

 of the other ingredients, as my former results were determined 

 from a much less quantity. I had begun this analysis before be- 

 ing aware of the fact, that my alcohol, sp. gr. 0*832, had dis- 

 solved some urate. Finding therefore that I had lost the means 

 of determining accurately the amount of chlorine and uric acid, 

 I have abandoned the inquiry for the present. However, the 



