490 LIQUID PARTS OF ANIMALS. 



The characters of the blue matter differed somewhat from those 

 described by Braconnot. It was soluble in alcohol, and when 

 the solution was evaporated, the blue sediment remained without 

 showing the least tendency to crystallization. It was soluble, 

 also, in boiling ether. Concentrated sulphuric acid dissolved it 

 and assumed a blue colour, but muriatic acid did not act upon it. 

 Nitric acid, when heated, destroyed it, and converted it into Wel- 

 ter's bitter principle. It was insoluble in caustic alkalies and 

 their carbonates. When burnt, it left a little phosphate of lime. 



15. Urine is sometimes mixed with blood. If the quantity of 

 blood be considerable, its presence is easily recognized by the 

 red colour. The globules of blood do not dissolve in urine. 

 They fall to the bottom, and may be easily distinguished by ex- 

 amining the sediment through the microscope. 



Urine containing blood always holds in solution some albu- 

 men, which coagulates when the urine is heated or mixed with 

 nitric acid. Such urine is always alkaline, unless the quantity 

 of blood be very small. The globules of blood in urine assume 

 an irregular form, and when treated with ammonia or acetic acid 

 dissolve completely. M. Lecanu has given the following method 

 of detecting minute quantities of blood in urine :* 



If the urine be ammoniacal it is neutralized by nitric acid, 

 and raised to the boiling temperature. The albumen coagulates 

 and falls to the bottom, carrying with it the globules of the blood. 

 The deposit, is collected on a filter and washed first with water, 

 and then with alcohol. It is then introduced into a matrass with 

 alcohol of O842, slightly acidulated with sulphuric acid, and the 

 liquid raised to the boiling temperature. The deposit, which was 

 at first reddish-brown, becomes colourless, while the alcohol as- 

 sumes a brownish colour, which a slight addition of ammonia 

 changes to red. The alcoholic solution being concentrated leaves 

 the colouring matter in the state of a black resinous-looking 

 matter, soluble in acetic ether and ammoniacal alcohol, to which 

 it gives a red colour, as soon as the alcohol and ammonia are 

 evaporated. If we calcine this matter, there remains a red ash, 

 soluble in muriatic acid, and the solution strikes a blue with 

 prussiate of potash. 



16. Dr Marcet, in the twelfth volume of the Medico-Chirur- 

 gical Transactions, described a singular variety of urine, which 



* Jour, de Pharm. xxvi. 206. 



