1855.] of Chemistry to the Preservation of Food. 77 



served provisions, with some of the organic matter ; and the latter, 

 at exclusion of that oxygen by the action of steam. A canister 

 of rice and meat, prepared by Appert, which had been in the 

 possession of Messrs. Fortnum and Mason* for ten years, was 

 opened under a saturated solution of salt ; the air it contained was 

 collected in the usual way, and when tried by the nitric-oxide 

 (NO*) test, was found free from oxygen. 



Bottles of choice fruit and green vegetables, in excellent condition, 

 were exhibited ; these had been prepared five or six years since by 

 Appert's process. M. Appert kindly sent from Paris for exhibition 

 on this evening a case of beef and soup, 3000 kilogrammes of which 

 he is now daily preparing for the French army in the Crimea. M. 

 Appert also exhibited specimens of more luxurious delicacies, as 

 cr6me au chocolat, pate de foies gras, pate de canard. 



The same process has been adopted and developed in this 

 country, with eminent integrity and success, by Mr. Gamble, who 

 has succeeded in preserving not only the substantial materials of' 

 food, but also fish and other luxuries of the table.f 



Two large tin canisters'of dressed meat, which had been prepared 

 by Goldner's process (expulsion of air by steam) in the year 1840, 

 in the presence of Dr. Faraday and Professor Graham, were ex- 

 hibited. As neither of these canisters had bulged out, it was 

 inferred that no gas had been formed, and that therefore no de- 

 composition of their contents had taken place. 



E. Preservation of Milk. 



Four processes of preserving milk were noticed ; each depended 

 on a different principle. 



1. The process of M. 3Iahru. 



This process preserves milk without addition of any substance 

 whatever. It consists essentially in the exposure of metallic bot- 

 tles, each containing about a quart of milk, to steam raised to the 

 temperature of 212^ Fah. These bottles are fitted with leaden 

 tubes, by means of which they were vertically suspended in the 

 steam from a chest filled with milk, so that there was constantly a 

 layer of milk above the extremities of the leaden tubes. After 



♦ [I am anxious to acknowledge the liberality with which Messrs. Fortnum 

 and Mason put a large and valuable collection of specimens at my disposal, 

 for experiment as well as for exhibition. — J. B.] 



t Among the specimens of Mr. Gamble's process were cairs head with 

 turtle-gravy, soup of ox-cheek, ox-tail, giblet, and mulligatawny, and mutton 

 broth, stewed rump-steaks, mackerel, stewed eels, lobsters, tripe, cream, and 

 butter. Some of these were opened and cooked during Mr. Barlow's discourse. 

 A scientific interest has attached itself to these aiticles of luxury, as well as 

 to those of M. Appert, because their preservation depends on the delicate ad- 

 justment of the heat employed in preparing them, between the temperature 

 which would destroy their flavour, and that which would be insufficient to 

 ensure their remaining uninjured in tropical climates. 



