SOAP BOILING. II 



make an experiment on the use of steam in the making of bating s . oa P 



rPL . .' , , , .,, e , lees by steajij. 



soap, lhis experiment Ave have made^ and with pert|ct 



success. 



I have the honour to lay before the Society, a piece of 

 soap of about ten cubic inches, made in my laboratory by 

 this new process, which required only six hours of boiling, 

 whereas sixty hours and more are necessary in the ordinary 

 method of making soap. 



From all the appearances that we observed in the course 

 of this experiment, and from its results, we think ourselves 

 authorised to conclude, that this new method of making 

 soap cannot fail to be advantageous in every respect} and 

 that it will soon be generally adopted. 



We propose to repeat the experiment on a larger scale ? 

 as soon as we shall be able to procure the necessary utensils, 

 and we beg the Society to appoint commissioners to be 

 present during its execution. 



As I intend to communicate to the Institute, upon a 

 future occasion, all the details of our experiment, with an 

 account of the apparatus we employed in it, I shall for the 

 present make only one observation on the probable cause 

 of the acceleration of the formation of soap, which we 

 observed. I believe that this acceleration is due, in great 

 measure, if not entirely, to a motion of a peculiar kind 

 in the mixture of oil and lye, occasioned by the sudden 

 condensation of the steam introduced into the liquor. It is 

 a sharp stroke, like that of a hammer, which made the 

 whole apparatus tremble. 



These strokes, which succeeded rapidly in certain cir- 

 cumstances, and which were violent enough to be heard at 

 a considerable distance, must necessarily have forced the 

 particles of oil and alkali to approach each other, and con- 

 sequently to unite. 



As the violence of these strokes diminished greatly as 

 soon as the liquid had acquired nearly the temperature of 

 the steam, I propose to supply this defect by a particular 

 arrangement of the apparatus in the experiment we ace 

 going to make. I shall divide the vessel into two parts, 

 by a horizontal diaphragm of thin sheet copper, and causing 

 ■4 slow current of cold water to pass thrqugh the lower . 



division 



