30 PATHOLOGICAL. 



sulphate solution; (2) 20 parts of tartaric-acid solution and 90 parts of sodium- 

 sulphate solution; (3) 30 parts of tartaric-acid solution and 80 parts of sodium- 

 sulphate solution; (4) 40 parts of tartaric-acid solution and 70 parts of sodium- 

 sulphate solution; (5) 50 parts of tartaric-acid solution and 60 parts of sodium- 

 sulphate solution; (6) 60 parts of tartaric-acid solution and 50 of sodium-sulphate 

 solution; (7) 70 parts of tartaric-acid solution and 40 parts of sodium-sulphate 

 solution; (8) 80 parts of tartaric-acid solution and 30 parts of sodium-sulphate 

 solution; (9) 90 parts of tartaric-acid solution and 20 parts of sodium-sulphate 

 solution; (10) 100 parts of tartaric-acid solution and 10 parts of sodium-sulphate 

 solution. To each glass an excess of crystallized sodium sulphate is added to the 

 point of insolubility. 



Of the blood to be examined i drop is mixed in a graduated tube prepared 

 for the purpose with an equal-sized drop of the acid-sulphate mixture. Into a 

 glass tube with a diameter of i mm. and drawn out at one extremity mercury 

 is sucked to a height of about 8 mm. so that the tube is filled to the tip. The upper 

 extremity of the thread of mercury is marked by the scratch of a file. The mer- 

 cury is now drawn into the tube until its lower border reaches the file-mark. The 

 upper border of the mercury is now marked with another file-scratch. In this 

 way the small measuring apparatus is improvised. 



In order now to test the blood, one drop of the tartaric-acid sodium-sulphate 

 mixture is sucked up to the lower mark, and then, after scrupulously drying the 

 tip, the blood is drawn up until the fluid reaches the upper mark. After again 

 cleansing the tip of the tube its contents are blown into a watch-glass, are well 

 stirred and then tested with reagent-paper. Successively the mixtures 2, 3, 4, 

 etc., are treated in the same way. The reagent-paper is cut into strips 3 mm. 

 wide, and these are partially dipped in the blood-specimens in the respective 

 watch-glasses. The blood-corpuscles collect about the immersed extremity of 

 paper, while the fluid is sucked up beyond and indicates the reaction. If the 

 test has been made successively in this manner with the mixtures from i to 10 

 it will be readily seen when the blue tint of the alkaline reaction ceases and the 

 red tint of the acid reaction begins. 



In human beings the blood can always be obtained directly from a small 

 needle-puncture. Exact suction into the tube can be effected with certainty and 

 convenience if the upper extremity of the meastiring glass is connected by means 

 of a short rubber tube with a hypodermic syringe, the movement of whose piston 

 through a twisting motion facilitates an exact degree of suction. All of the tests 

 must be completed with equal rapidity and at the same temperature. 



The degree of alkalinity in the adult will in general be satisfied by mixture 

 5 or 6, and in the child by mixture 4. If all parts of the blood are uniformly dis- 

 solved previously by addition of water this solution, which obviously can no 

 longer be designated blood, exhibits a somewhat higher degree of alkalinity. 

 If blood is tested slowly by the method described the alkalinity will be that of 

 such a solution. 



Pathological. Persistent vomiting and chlorosis are attended with increased 

 alkalinity, while diabetes, as well as cachectic states, rheumatism, uremia, leuke- 

 mia, profound anemia, high fever, cholera, carbon-monoxid poisoning, and degen- 

 eration of the liver are attended with diminished alkalinity. Poisons that cause 

 destruction of red blood-corpuscles likewise bring about reduction in the alkalinity. 



Blood has a peculiar odor. 



This "halitus sanguinis" differs in human beings and in animals, and depends 

 upon the presence of volatile fatty acids. If sulphuric acid be added to blood, 

 and these acids are in consequence set free from their combination with the alkali 

 of the blood, the characteristic odor appears more distinctly. 



The blood possesses a salty taste, derived from the salts dissolved in 

 the blood-plasma. 



The specific gravity of the blood is 1058 (from 1046 to 1067) in men, 

 and from 1051 to 1055 i n women, while the blood of children has a lower 

 specific gravity. The specific gravity of the red blood-corpuscles is 

 1105, that of the plasma from 1027 to 1028.3. This fact explains the 

 tendency of the former to sink to the bottom. 



Method of Determination. For clinical investigation the following method (a 

 modification of that described by Roy) can be recommended. In a glass tube, 



