SCIENCE SIFTINGS

New Zealand Tablet, 17 June 1920, Page 46

SCIENCE SIFTINGS

(By “Volt.”)

Ancient and Modem Breadmaking. - It is not generally known where and when loafbread originated, but some believe that credit is due to the Chaldeans. Previous to their captivity, the Israelites made unleavened cakes, but later they learned from the Egyptians the art of leavening dough and baking bread. The Romans gained their knowledge of bread-making from the Greeks and spread the art throughout the countries they conquered. When the Romans went to Scotland they found the natives baking their bread on a ring- of flat stones about a fire, which the conquerors called “grerdiol,” meaning girdle. About 50 years ago in some old Welsh farmhouses there might be found flat, circular iron plates or bake-stones, which were somewhat similar to the Scottish girdle. It is probable that England learned its bread-making from the Romans, but for many centuries there were practically no public bakers. Also, bread made from wheat was a luxury, and the poor were forced to utilise rye or barley, and sometimes peas, beans, or oats. In 1596 Thomas Cozan published a book called The Haven of Health, a part of which dealt with breadmaking. Mr Cozan claimed for good bread qualities upon which we insist to-day. Light bread was then accomplished by much working of the flour and leaving the paste in a warm place for fermentation. Yeast came into use in 1634 and caused considerable opposition at first, as it was thought to be detrimental to health. The Passing of Petrol, Professor Harold B. Dixon, F.R.S., who is a member of the Inter-Departmental Committee on Alcohol Motor Fuel, and is in charge at the Manchester Dniversity of all research and' experiments in connection with the discovery of a suitable alternative fuel to petrol, claims same very real progress as a result of his ■ investigations. Professor Dixon is still conducting inquiries into the different values of ordinary alcohol, ether, benzole, and various mixtures of all three. In his. opinion, according to the Manchester motoring correspondent of the Daily Mail, we “can rid ourselves per--mauently of the petrol incubus and more than fill the enormous demands of motor transport all over the Empire by taking sun-power as it comes and not by draining away the limited store of old sun-products still available.” “My researches so far,” said Professor Dixon to the correspondent, “have convinced me that we can get all the motor fuel we need from a single tree or' other form of vegetation. I say * tree,’ because I believe the mahua tree, which grows freely in India, yields a large proportion of alcohol from its flowers when they are treated. But a good yield is also obtained from molasses, of which there is a huge supply in the West Indies and other accessible parts of the Empire. “ Pure alcohol, as you know, needs a higher compression in the ordinary motor-engine than we use to-day. It is also difficult to start up from cold. But mixed with either- benzole or, what I regard as infinitely more practical, ether, it becomes as tractable a fuel as any we have now. Ether is produced, of course, from the alcohol itself. “I. am still experimenting with compressions to find out exactly at what point different strengths of the alcohol mixtures are most efficient all round.” “How long would it be before such a supply of fuel could begin ?”'Professor Dixon was asked, - “That does not worry me at all,” he replied. “From the moment the Government sanction its manufacture and when the raw., material and plant is available, it. is only a question of ordinary - chemical process to. extract the stuff. A few weeks. It does not take long to make.”