AMERICAN INSTITUTE. 565 



eaten, presents a larger surface, viz: the surface of the air-lioles, or cells 

 — to the solvent in the stomach. It, therefore, digests more easily, and is 

 more healthful. Fermentation changes a portion of the starch to sugar 

 and carbonic acid. The sugar is pleasant and wholesome, while the car- 

 bonic acid serves to aerate or raise the bread. In the old method of fer- 

 menting, by means of leaven, the leaven, or fermenting dough, was liable 

 to become putrid, and highly offensive to the smell. This can hardly occur 

 with yeast, which is, therefore, preferable. 



Within the last few years, baking powders and self-raising flour have 

 come into use ; articles which cannot be taken, for many years, without 

 injury to the stomach, and consequent dyspepsia. Baking powders are, 

 simply, cream of tartar and carbonate of soda ; but these cannot be had 

 pure. Dr. Churchill, of Paris, has ascertained that the effect of hypo- 

 phosphate of soda, on the system, is most injurious, and this is almost 

 constantly to be found in connection with, or resulting from, the common 

 baking powders. Carbonate of ammonia would be better than of soda, 

 but it cannot be got pure either. 



Prof. Hedrick showed that there was a chemical change, the starch 

 being changed into dextrine, which is more soluble and fitter for nutrition. 

 The change, by fermentation, is from starch to dextrine, then to sugar, 

 then to alcohol, lastly to acetic acid. The sourness then shows that the 

 fermentation has been carried too far, and the dough has been deteriorated. 



On motion, a committee of three was appointed to arrange the subject 

 of adulteration of food, for discussion by the Club. 



The Association adjourned to Thursday, the 16th instant. Subject: — 

 ** Superheated Steam." 



American Institute, Polytechnic Association, 



Februarij 16/A, 1860. 



Prof. Mason, Chairman. John Johnson, Esq., Secretary pro tem. 

 The Committee on adulterations of food, reported that it was inexpedient 

 to divide the subject into separate heads for discussion. 



REPORT OF the SPECIAL COMMITTEE ON PRANKLINITE. 



Prof. C. Mason, chairman of the special committee on franklinite, read 

 a report from which what follows is an extract. 



The plants and animals of the earth were a birthday gift to the primitive 

 men. In the reproduction of each kind they foresaw the constancy of their 

 supplies. And as the vital kingdom supplied their wants, they were not 

 careful to learn the changes of the mineral kingdom. 



In the town of Franklin, Sussex County, N. J., within 70 miles of 

 New York, is found the only locality of ore where the three metals of iron, 

 manganese and zinc, known as franklinite, are molecularly combined, and 

 either monometrically or amorphously crystallized. Its precise position, 

 geologically, is in a belt of altered granular' limestone, resting uncomform- 



