1813.] Scientific Intelligence. 59 



with a curious table of the days of the month at which the 

 different migrating birds usually make their appearance at 

 Kendal, either on their way to the north or to the south. 



Article XII. 



SCIENTIFIC intelligence; and notices of subjects 



CONNECTED WITH SCIENCE. 



I. Concretion on the Elm. 



I lately received from William Elford Leach, Esq. a concre- 

 tion of a brownish grey colour and stony appearance, which he 

 had found deposited on the bark of an elm tree, I believe in 

 Hyde Park. All the specimens of it were mixed with more or 

 less of the bark of the tree. I subjected it to chemical analysis, 

 and found it composed of the following constituents: — 



Old bark 28 



Carbonate of potash 39 



Carbonate of lime 32 



Carbonate of magnesia 1 



100 



Another specimen analysed contained no less than 48 per 

 cent, of bark. The other constituents were nearly in the above 

 proportion. Vauquelin long ago published the analysis of a 

 concretion from the elm containing the very same constituents; 

 but its appearance was different. He describes the substance 

 which he examined as white, and says that he could distinguish 

 crystals in it. The concretion collected by Mr. Leach was dark 

 grey, and no crystals could be detected in it, by the most careful 

 examination. 



II. Calculus from the Urethra of a Hog. 



I received sometime ago from Mr. Colville, surgeon in Ayton, 

 Berwickshire, a calculus extracted from the urethra of a hog, which 

 deserves to be described. It is nearly spherical, weighs 44 - 2 

 grains, its specific gravity is 1-5'J.'), it is white, has a silky lustre, 

 and is composed of a congeries of very small crystals, which, as 

 far as can be judged by the eye, consist of flat four-sided prisms. 

 The calculus is soft, so that the crystals are very easily separated 

 from each other. This calculus is composed entirely of phos- 

 phate of lime; at least 1 have not been able to detect any other 

 matter in it. When heated with potash no smell of ammonia 

 can be perceived, which 1 consider as excluding the presence of 



