84 DISEASES DUE TO PROTOZOA 



The jcBces show increased excretion of bile and iron, both from 

 blood destruction. Stercobilin is increased. 



The sweat has a peculiar odour and is toxic to rabbits. 



Goose skin may be caused by some malarial toxin acting on un- 

 striped muscle, affecting the erector pilorum. 



Hcemozoin is the black dust-like grains of pigment formed from 

 haemoglobin and distributed over the body after the rupture of the 

 red cells. Phagocytes remove it to the connective tissue, e.g., the 

 liver and spleen. It is soluble in alkalies, entirely and rapidly in 

 ammonium sulphide, but not in water, alcohol or acids. It contains 

 an organic compound of iron which will not give the Berlin blue re- 

 action. Eventually it disappears from the body, but how is not 

 known . 



It is peculiar to diseases caused by malarial parasites except 

 melanotic tumours, but in the latter instances it is never seen in the 

 blood-vessels. Intravascular black pigment is pathognomonic of 

 malaria. It is most abundant in the splenic vein and lymphatic 

 glands at the hilum of the liver. 



HcBmosiderin is a yellow pigment found as yellow granules in the 

 parenchyma cells of the liver, spleen, kidneys, pancreas, bone-marrow, 

 capillary epithelium, and less frequently in the leucocytes. 



It contains an inorganic compound of iron which gives the Berlin 

 blue reaction (ammonium sulphide and double cyanide of iron and 

 potassium). It is insoluble in alkalies, acids and alcohol (Manson). 



It is not peculiar to malarial diseases, but may occur in any where 

 there has been marked blood destruction, as in haemoglobinuria, 

 pernicious ana&mia, extensive burns and toxic poisoning by such agents 

 as potassium chlorate and pyrogallic acid. 



The liver converts the free haemoglobin into bile pigment, which, 

 when in excess, overflows, as it were, causing bilious diarrhoea and 

 vomiting; consequently polycholia is a constant feature of malaria. 

 The yellow tinging of the skin and sclerae may be due to free hemo- 

 globin and not to cholasmia as a result of bile absorption as once 

 commonly believed (Manson). This yellow pigment is probably pre- 

 cipitated haemoglobin, stored up and waiting to be worked off by a 

 busy liver. Should the haemoglobin go beyond this it overflows, and 

 then we have haemoglobinuria. 



The red cells. — The body (150 lbs.) contains about 25,000,000,000,000 

 red cells. To examine all these under the microscope at the quickest 

 rate would take over 1,000 years (Ross). 



In severe infections 12 per cent, are infected, i.e., 2,000,000,000,000. 



If only I in 100,000 corpuscles are infected, i.e., 250,000,000, there 

 will be but little manifested of the disease (Ross). 



