MECHANICS AND USEFUL ARTS. 



rise to the. surface of the water, and bubbles of gas begin to be evolved 

 from them, they are immediately spun. 



In spinning, the guts are chosen according to their size ; combined 

 with throe or more, according to the volume of the string required, 

 they are fastened upon a frame, and then alternately put in connexion 

 with the spinning-wheel, and submitted to the required torsion. This 

 operation performed, the strings, left upon the frame, are exposed for 

 some hours to the vapor of sulphur, rubbed with a horse-hair glove, 

 submitted to a new torsion, sulphured again, further rubbed, and 

 dried. 



The dried strings, rolled upon a cylinder and tied, are rubbed with 

 fine olive oil, to which one per cent, of laurel oil has been previously 

 added. The oil of laurel is supposed to keep the olive oil from be- 

 coming rancid. 



The gut-strings employed by turners, grinders, and for cleaning 

 cotton, &c., are made with the intestines of oxen, horses, and other 

 animals. These, cleared by putrefaction of the mucous and peritoneal 

 membranes, and treated by a solution of carbonate of potash, are cut 

 into straps by means of a peculiar knife, and spun in the same way as 

 the musical strings. The uses of bladders and gut for holding lard, 

 for covering gallipots and jars with preserves, as cases for sausages, 

 polonies, &c., and other domestic purposes, are well known. Lately, 

 however, the vegetable parchment, as it is termed (which is ordinary 

 paper steeped in sulphuric acid), has come into extensive use for this 

 purpose. 



Insufflated, or inflated guts, are chiefly employed for the preserva- 

 tion of alimentary food. They have to pass through a long series of 

 modifications and processes, before becoming fit for use. The end of 

 these preparations is, to free the muscular membrane of the intestine 

 from the two other membranes covering it, the peritoneal and the 

 mucous. 



The first operation of scouring consists in freeing, by means of a 

 knife, the gut from the grease attached to it, and also of the greatest 

 part of the peritoneal membrane. The scoured guts are washed and 

 turned inside out, then tied together, put into a vat without any more 

 water than that adhering to them, and left in this state to undergo a 

 putrid fermentation. The time required for this operation will be from 

 five to eight days in winter, and two or three days only in summer. 

 If the fermentation were pushed too far, the guts would be disorgan- 

 ized : to avoid this inconvenience, the workmen are often obliged to 

 add some vinegar, in order to neutralize the ammoniacal compounds 

 formed, and also because fermentation is slow in the presence of acids. 

 After this fermentation, the mucous membrane is completely decom- 

 posed, and the remaining portions of the peritoneal membrane are 

 easily taken off. The guts are then well washed, and insufflated (in- 

 flated). 



This operation is performed in the same way as swelling a bladder, 

 with this difference, that the extremity of the gut is tied by a ligature, 

 serving also to join a new gut insufflated (inflated) in the same way. 

 During this operation, the guts exhale the most noxious smell, and 

 workmen employed at such work could not blow or insufflate many 

 days in succession without having their health affected. 



