196 



artery was divided into two branches, to supply the lungs. These 

 vessels were of small diameter. 



The pulmonary veins were four in number ; but the area of these, 

 and that of the vessel which acted as the pulmonary artery, did not 

 exceed half the usual dimensions. 



The child, while alive, was seen by Dr. Combe, who did not 

 observe that its respiration, temperature, or muscular action, were 

 materially affected. 



On a Method of analysing Stones containing fixed Alkali, by Means of 

 the Boracic Acid. By Humphry Davy, Esq. F.R.S. Professor of 

 Chemistry in the Royal Institution. Read May 16, 1805. [Phil. 

 Trans. 1805, p. 231.] 



The method of analysis here described by Mr. Davy is founded on 

 the attraction of the boracic acid for the simple earths, which is con- 

 siderable at the heat of ignition, and on the ease with which the 

 compounds formed with them are decomposed by the mineral acids. 



The process is as follows : 100 grains of the stone to be examined 

 must be fused for about half an hour, in a strong red heat, with 200 

 grains of boracic acid : an ounce and a half of nitric acid, diluted 

 with seven or eight times as much water, must be digested upon the 

 mass till the whole is decomposed ; and the fluid must then be re- 

 duced, by evaporation, to an ounce and a half or two ounces. 



If the stone contain silex, it will now be separated : this must be 

 collected upon a filter, and washed with distilled water till freed from 

 the boracic acid and all other saline matter. 



The water that has passed must be mixed with the other fluid, and 

 the mixture evaporated till it is reduced to a convenient quantity, 

 for instance, half a pint. It must then be saturated with carbonate 

 of ammonia, and boiled with an excess of this salt till all precipitable 

 matter has fallen to the bottom of the vessel. 



The earths and metallic oxides must be separated by the filter, and 

 to the filtered liquor must be added nitric acid, till it tastes very 

 sour : it must then be evaporated till the boracic acid appears free. 



The fluid must be again passed through the filter, and evaporated 

 to dryness ; when, by exposure to a degree of heat equal to 450 of 

 Fahrenheit, the nitrate of ammonia will be decomposed, and the ni- 

 trate of fixed alkali will remain in the vessel. 



The remaining earths and oxides Mr. Davy has separated by the 

 usual processes. The alumina he has separated by solution of pot- 

 ash ; the lime by sulphuric acid ; the oxide of iron by succinate of 

 ammonia; the manganese by hydrosulphuret of potash; and the 

 magnesia by pure soda. 



