In answer to a call we made upon our correspondents in No. 35 of the present volume, for some cheap and practical means which would disinfect the United States steam frigate Susquehanna, we have received many suggestions, and among the most original we select the following :— First—It is proposed that the authorities procure five hundred bushels of oyster shell lime, fresh and warm from the kilns, and distribute it through the hold, and between her decks ; then close her hatches, and allow the lime to become air-slacked, and the gas emitted to penetrate the ship. This, we fear, would not answer, as the only action that we could depend upon in the lime would be the absorption of all carbonic acid and moisture that may be in the atmosphere, as in slacked lime there is no gas emitted. Second—It having been observed in Cornish mines that water was frozen at the bottom of the air pipe, it is suggested that similar means be used in freezing out "yellow Jack." The apparatus consists of an engine and compression air pumps at the mouth, and a long air pipe leading to an engine at the bottom. The air pumps in question were supplied with a small stream of water to prevent leakage, the heat resulting from the compression was so great as to convert a part into steam ; but before the air reached the lower engine it was cooled still under pressure to the temperature of the atmosphere in the mine. When the air was released from pressure at the exhaust of the lower engine, the water was discharged as ice. By means of a few hundred feet of gas pipe and a weighted valve, air with water could be forced into the ship, and taking advantage of the observation described, " yellow Jack" would be frozen out. This, we think, is an admirable proposition, and worthy the attention of the authorities. Third—A gentleman sends us the prospectus of Hellard's Concentrated Gaseous Chlor-id, which, he asserts, is a most powerful disinfectant ; but as he has not given us its composition, and as also he is in communication with the authorities, we can only notice the communication thus briefly. There is still one more plan that we must notice one—one that comes from the assignee of Schooby's patent for producing currents of cold air. He proposes to cause air to pass through a mixture of ice and salt into the hold of the ship, the draft being created by the coldness, and a long chimney at the other end of the ship. It would require a fan blast or some other means of drawing this cold air through the ship, as it would never bring about sufficient ventilation by its mere low-ness of temperature.