834 APPENDIX. 



distinct milk-curdling ferment exists in the stomach. W. Koberts has 

 shown that a similar but distinct ferment exists in pancreatic extract, 

 which acts best in an alkaline medium, next best in an acid medium, 

 and worst in a neutral medium. The ferment of rennet acts best in an 

 acid medium, and worst in an alkaline, the reaction ceasing if the alka- 

 linity be more than slight. Also in the Succus entericus. 



In addition to the above ferments, many others most likely exist in 

 the body, of which the following are the most important: 



(6.) Fibrin-forming ferment (Schmidt), (see p. 136 et seq.)^ found in 

 the blood, lympli and chyle. 



(7.) A ferment which converts glycogen into glucose in the liver; 

 being therefore an amylolytic ferment. 



(8.) Myosin ferment. 



CARBO-HYDRATES OR AMYLOIDS. 



The divisions of carbo-hydrates, and the chief substances forming 

 each class with their properties, have been already given (p. 122 et seq). 

 The following additional information may be useful. 



The glucoses may be considered as the aldehydes of mannite, thus : 



CH 2 OH ) CH 2 OH ) 



(OH OH) 4 \ C 6 Hw 6 , (CH OH) 4 \ 6 H 12 6 



CH 2 OH ) CO H ) 



mannite. glucose. 



The Saccharoses or sucroses are made up of two volumes of glucose 

 minus one molecule of water. 



CG Hi 2 OG + CG Hi 2 OG H 2 = Ci 2 H 22 On. 



The amyloids are anhydrides of the glucoses, C 6 H i2 OG H 2 = 

 CeHioOs. 



Tests for Glucose. (i.) Trammer's. This test depends upon the 

 power sugar possesses of reducing copper salts to their sub-oxide. It is 

 done in the following way : An excess of caustic potash and then a 

 solution of copper sulphate, drop by drop, are added to the solution 

 containing the sugar in a test-tube, as long as the blue precipitate which 

 forms redissolves on shaking the tube. The upper portion of the fluid is 

 then heated, and a yellowish-brown precipitate of copper suboxide ap- 

 pears. The test may also be done by taking only a drop or two of the 

 copper sulphate solution. 



(ii.) Moore's. If a solution of sugar in a test-tube is boiled with 

 caustic potash, a brown coloration appears. 



(iii.) Fermentation. If a solution of sugar be kept in the warm plate 

 for a time after the addition of yeast, the sugar is converted into alcohol 

 and carbon dioxide. (C 6 H 12 6 = 2C 2 H 5 OH + 2C0 2 .) 



(iv.) Bottcher's test. A little bismuth oxide or subnitrate and an 

 excess of caustic potash are added to the solution in a test-tube, and the 

 mixture is heated ; the solution becomes at first gray and then black. 



