43 8 SCIENCE PROGRESS 



and their use allowed. The fact that most of the formulae in 

 use are empirical and not molecular should be emphasised — that 

 common salt, for example, is represented only empirically by 

 the formula NaCl. The hideous habit of speaking of substances 

 not by name but by naming the letters in their formulae should 

 never be allowed to grow up. 



Now will come the stage at which the conception of structure 

 should be developed by the thorough study of alcohol. The 

 foundation will thus be laid for the profitable study of physio- 

 logical problems, in so far as is necessary to obtain an insight 

 into the all-important subject of food and its functions. 



At an early period of the course a most careful study will 

 have been made of plant growth from start to finish, in the 

 sense that development will have been followed, watched and 

 recorded through all its stages — but not elucidated. Now comes 

 the time to elucidate the processes of growth. Flour is easily 

 separated into starch and gluten, milk into fat and curd, meat 

 into flesh and fat ; the existence of two main classes of food 

 materials being thereby established — the non-nitrogenous and 

 the nitrogenous — the changes which attend germination may 

 be followed with advantage. Commencing with the barley 

 grain, its behaviour towards water alone and towards water 

 containing acids, salts, etc., in solution may be studied from 

 the point of view of Prof. Adrian Brown's recent striking 

 observations, which demonstrate the existence, as an outer 

 covering of the seed, of a membrane which, in a most mar- 

 vellous way, prevents the entry of nearly all substances other 

 than water into the grain and in like manner hinders the exit 

 from the grain of soluble matters as these are formed during 

 germination, thus preventing the loss of the food materials 

 available for the development of the young plantlet. The 

 disappearance of the starch — the loss of dry matter — is easily 

 followed experimentally and the nature of the process made 

 clear by studying the action of unboiled and boiled malt-extract 

 on starch paste. The existence and mode of action of enzymes 

 having been thus demonstrated, the oxidation process may be 

 followed, qualitatively and quantitatively ; it is desirable to use 

 seeds in which fatty matters are the reserve material as well as 

 starchy seeds for such experiments, in order to make clear the 

 function of both starch and fat as foods. 



The liberation of oxygen and the formation of starch under 



