262 PHYSIOLOGICAL CHEMISTRY 



hydrogen peroxide or old turpentine. It has also been shown 1 that 

 those milks which respond positively, fail to do so after boiling. In the 

 case of blood the test is positive both before and after boiling the blood 

 for 15-20 seconds. Pus does not respond after boiling. Old, partly 

 putrified pus gives the test even without the addition of hydrogen 

 peroxide or old turpentine, whereas fresh pus responds upon the addi- 

 tion of hydrogen peroxide. Saliva gives a positive reaction only in 

 case blood or pus is present. Certain plant extracts give the test before 

 but not after boiling for 15-20 seconds. Buckmaster has advocated 

 the use of an alcoholic solution of guaiaconic acid instead of an alcoholic 

 solution of guaiac resin. He claims that he was able to produce the 

 blue color upon the addition of the guaiaconic acid to milk only when 

 the sample of milk tested was brought from the country in sterile bottles, 

 and further, that no sample of London milk which he examined responded 

 to the test. In the application of the guaiac test to the detection of 

 blood, he states that he was able to detect laked blood when present in 

 the ratio 1:5,000,000 and unlaked blood when present in the ratio 

 1:1,000,000. This author considers the guaiac test to be far more 

 trustworthy than is generally believed. 



Lymph may be considered as the "middle man" in the transactions 

 between blood and tissues. It is the medium by which the nutritive 

 material and oxygen transported by the blood for the tissues is brought 

 into intimate contact with those tissues and thus utilized. In the 

 further fulfillment of its function, the lymph bears from the tissues 

 water, salts and the products of the activity and catabolism of the 

 tissues and passes these into the blood. Lymph, therefore, exercises 

 the function of a "go-between" for blood and tissues.^ It bathes every 

 active tissue of the animal body, and is believed to have its origin partly 

 in the blood and partly in the tissues. 



In chemical characteristics, lymph resembles blood plasma. In fact, 

 it has been termed "blood without its red corpuscles." Lymph from 

 the thoracic duct of a fasting animal or from a large lymphatic vessel of 

 a well-nourished animal is of a variable color (colorless, yellowish or 

 slightly reddish) and alkaline in reaction to litmus. It contains 

 fibrinogen, fibrin-ferment and leucocytes and coagulates slowly, the clot 

 being less firm and bulky than the blood clot. Serum albumin and 

 serum globulin are both present in lymph, the albumin predominating 

 in a ratio of about 3 or 4: i. The principal inorganic salts are sodium 

 salts (chloride and carbonate), whereas the phosphates of potassium, 

 calcium, magnesium and iron are present in smaller amount. 



Substances which stimulate the flow of. lymph are termed lympha- 



1 Leary: Private communication. 



