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The albumenoids, whether of vegetable or animal origin have been 

 characterised as " infusible, non-volatile amorphous solids, neutral in 

 re-action and indifferent in combination." Thus it seems that their 

 characterising element nitrogen has been able to impress its own 

 individuality upon them, and the most characteristic chemical re-action 

 they can show in one indicating the presence of nitrogen. When they 

 are well dried and heated with soda lime, or even alone, they give off 

 ammonia, which can be recognised by smell and reaction. There is 

 always produced a disagreeable smell on burning nitrogenous sub- 

 stances (wool) ; not so when nitrogen is absent ; (cotton). 



The composition of animal 3nd vegetable albumenoids is very 

 nearly the same, and their chemical properties very similar. It is not 

 usual to recognise the properties of white of egg in vegetable products, 

 but it can be shown that a similar substance may be obtained from 

 wheaten flour. On shaking some of it up with cold water, and filtering, 

 a solution is obtained which coagulates on heating, on admixture with 

 dilute acids, alcohol, &c. 



The precipitate produced when the cold solution from wheat flour 

 is heated is called plant albumen, but if this be filtered off and a little 

 acid added to the filtrate we obtain a separation of what is called 

 legumin or vegetable casein. This sort of casein is the chief albumenoid 

 formed in the leguminosoe, in peas and beans, in their little laboratories, 

 whenever they undertake, as is their proud privilege, to utilise the 

 nitrogen of the atmosphere. 



But the proteids which the cellular tissue of a plant manufactures 

 from its nitrogenous food are not all soluble in water. In fact, however 

 soluble they may be in the plant itself, comparatively little of them in 

 quantity is found to be so after we get them into our hands. If we make 

 a little dough from wheaten flour and knead it enclosed in a piece of 

 calico, either in water, or with occasional immersion, the starch of the 

 flour exudes through the small holes in the cloth, along with the soluble 

 proteids. If this kneading is continued until no more white particles can 

 be kneaded out, and the cloth is then opened there is found inside a 

 grey coloured, elastic, sticky substance, which is known as " crude 

 gluten." Its stickiness is characteristic ; the Germans call it " kleber," 



