58 On the Means of preserving Provisions and Goods. 



tina pushed to a greater distance from the pupil when we are view- 

 ing near objects. Dr. Tliomas Young differs from Kepler; Des- 

 cartes from !)oth; Haller from all: with a crowd of others whose 

 opinions I think it umiccessary to mention. 



I remain, sir, your obedient servant, 

 Cork, April 1, 1819. " JoSEFH ReaDE, M.D. 



X. Ohsei'vations on the Means of preserving Provisions and 

 Goods. By Joseph MacSweeny, M.D. 



To Mr. TiUoch. 



A he plan for preserving provisions, which I intend to suggest 

 in this paper, promises to be useful on account of the facility with 

 which it may be put in practice. If proposed before, it has not 

 excited attention, while more complicated and more expensive 

 processes have been attended to. I hope that this paper will be 

 the means of drawing attention to a matter of such consequence 

 to the public, particularly when it is in the power of every house- 

 keeper to put the plan into execution. I had determined a con- 

 siderable time ago to commence experiments to try to jireserve 

 meat by keeping it in water (previously boiled) covered with a 

 layer of oil to protect it from the agency of the atmosphere. 

 After reading the interesting experiments of Dr. Marshal Hall, I 

 resolved to add bright pieces of iron or iron-filings to the water, 

 for the purpose of depriving it of the oxygen not expelled by 

 boiling. It is now more than seven weeks since I put some fresh 

 meat with iron in water, boiled and covered with a thick layer of 

 oil. The meat has exactly the same appearance now tiiat it had 

 the first day. It may be necessary to add that I kept the glass- 

 vessel containing it in a dark place. Vegeta!)le substances may- 

 be preserved in the same way. Delicate substances of this kind 

 when kept in a dark place appear only to suffer from the solvent 

 powerof the water*. In the same way cutlery may be kept un- 

 tarnished, wlien the precaution is taken of adding some iron-filings 

 or bright pieces of iron to the water some time beforehand. 

 After twenty-six days, I removed a piece of iron from a solution of 

 common salt covered with oil, and found it not tarnished in any 

 degree. Goods of every kind may be preserved from decay on 

 the same principle. Lest any, such as linen or cotton goods, 

 might suffer from the iron, it shor.ld be put in small timber boxes 

 and let down through the oil into th.e water, so that it could abs- 

 tract the oxygen without coming in contact with the goods. 



• The solvent power of tlie water may be diminished by adding sugar 

 and gum. 



When 



