340 THE BLOOD. 



apparently contains a number of other ferments. N. Sieber could 

 thus demonstrate three different oxidizing ferments, which are capa- 

 ble not only of decomposing glucose (Lepine's glucolytic ferment), 

 but also disaccharides and polysaccha rides. Schumm has demon- 

 strated a proteolytic ferment, others a lipase, etc. Opie mentions 

 an antileucoprotease (antitrypsin). On immunization with various 

 foreign cells and cell products, moreover, corresponding antibodies 

 are encountered in the blood, which in part at least may be related 

 to ferments. The list includes the antitoxins, the agglutinins, the 

 cytolysins (bacteriolysins, ha3molysins, spermatolysins, etc.), pre- 

 cipitins, coagulins, antiferments, anti-aggressins, etc. 



The remaining solids which are found in both plasma and serum 

 are, as has been pointed out, present in only very small amounts. 

 The most important of these is glucose. Its amount varies between 

 1 and 1.5 pro mille, and is but little influenced by the character of 

 the food unless a large excess of carbohydrates has been ingested. 

 In such an event the amount may increase to 3 pro mille, or even 

 higher, but it then appears also in the urine, whereby a further 

 increase is prevented. Larger amounts, such as 9 pro mille, are 

 found only under pathological conditions. 



In addition to glucose, another reducing substance is found in the 

 blood, which to a certain degree is fermentable and is soluble in 

 ether. From the researches of P. Mayer, it appears that this sub- 

 stance is a conjugate glucuronate. 



Neuberg and Strauss have shown that at times traces of laevulose 

 can also be demonstrated in the blood-serum, and that artificially 

 a laevulossemia can be produced in certain individuals following the 

 ingestion of 100 grammes. The presence of jecorin, which has 

 repeatedly been reported, is doubtful. 



Glycogen is constantly present in normal blood. Its amount, 

 however, is subject to great variations. As a rule, traces only are 

 found, but it may increase at times to 1.56 per cent., as calculated 

 for the blood as a whole. Larger amounts are seen under patho- 

 logical conditions. 



Fat is normally found to the extent of from 0.2 to 0.3 per cent., 

 but may be greatly increased by the ingestion of much fatty food, 

 as also in various pathological conditions. 



Urea is likewise found in only very small amounts under normal 

 conditions (0.016 to 0.020 per cent.), while in disease much greater 

 quantities may be encountered. Ammonia is said to be present in 

 normal blood to the amount of 0.001 per cent. 



The further occurrence in the blood of soaps, cholesterin, and 

 lecithins, as also of uric acid, kreatin, carbaminic acid, paralactic 

 acid, hippuric acid, etc., has been mentioned. In addition Tanella 

 claims to have found small amounts of phosphocarnic acid in the 

 blood. All these bodies are found in only extremely small amounts, 

 and need not be considered at this place. The pathological constit- 



