MECHANICS AND USEFUL ARTS. 81 



wheat-flour, the dough rolled and cut into the form of biscuits, and 

 then desiccated, or baked, in an oven at a moderate heat. The cook- 

 ing, both of the flour and the animal food, is thus complete. The 

 meat-biscuits thus prepared have the appearance and firmness of the 

 nicest crackers or navy-bread, being as dry, and breaking or pulveriz- 

 ing as readily as the most carefully made table-crackers. It is pre- 

 served in the form of biscuit, or reduced to a coarse flour or meal. It 

 is best kept in tin cases hermetically soldered up ; the exclusion of air 

 is not important, as humidity alone is to be guarded against. I have 

 seen some of the biscuit perfectly fresh and sound that have been 

 hanging in sacks since last July in Mr. Borden's kitchen ; and it is to 

 be borne in mind, that in this climate articles contract moisture and 

 moulder promptly, unless kept dry by artificial heat. 



" For making soup of the meat-biscuit, a batter is first made of the 

 pulverized biscuit and cold water ; this is stirred into boiling water ; 

 the boiling is continued some ten or twenty minutes ; salt, pepper, and 

 other condiments are added to suit the taste, and the soup is ready for 

 the table. I have eaten the soup several times ; it has the fresh, 

 lively, clean, and thoroughly-done or cooked flavor that used to form 

 the charm of the soups of the Rocher de Cancale. It is perfectly free 

 from that vapid, unctuous, stale taste which characterizes all prepared 

 soups I have hitherto tried at sea and elsewhere. Those chemical 

 changes in food which, in common language, we denominate cooking, 

 have been perfectly effected in Mr. Borden's biscuit by the long-con- 

 tinued boiling at first, and the subsequent baking or roasting. The 

 soup prepared of it is thus ready to be absorbed into the system with- 

 out loss, and without tedious digestion in the alimentary canal, and is 

 in the highest degree nutritious and invigorating. It is to be noted, 

 moreover, that the meat-biscuit is manufactured without salt, pepper, 

 or any condiment or chemical antiseptic whatever. We have thus an 

 article of food, partly farinaceous and partly animal, such as the system 

 requires for long-continued use ; it is easily preserved, in all climates, 

 seasons, and circumstances, is in a form the most concentrated and 

 convenient, is prepared easily and quickly, and is, moreover, cheap." 



IMPROVEMENTS IN THE PRODUCTION OF LIGHT AND HEAT. 



AN English patent was granted, May 22, to M. Gillard, of Paris, 

 for certain improvements in the production of heat and light. The 

 invention, according to the specification, consists in certain apparatus 

 and processes for producing hydrogen gas, by the decomposition of 

 water, and its application to heat and light. The means by which the 

 gas is obtained are : 1. by the incandescence of iron ; 2. by carbon ; 

 3. by magnets. First, the means of obtaining hydrogen by decompos- 

 ing water by heated iron. Into retorts fitted for the purpose with iron 

 tubes, chains, wire, or spirals of the same metal rendered incandescent, 

 the patentee introduces steam supplied from any source, or even pro- 

 duced by means of water injected into the retorts. The oxygen of 

 the water combines with the iron, and the hydrogen is conducted into 

 a refrigerant, and then into a gasometer for use. When the iron is 



