548 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



sensibly and considerably reduce the temperature of the lowest 

 stratum of the air. As in the case of all other substances, snow can- 

 not be reduced from the solid to the liquid state, without absorbing 

 heat, and when it is melted by means of salt, the heat is absorbed 

 from the atmosphere. The air is not only made colder, but it is 

 rendered more luoist. "Warm air will contain more water than 

 cold air, and when the temperature of the air is reduced, the 

 invisible vapor which it contained is condensed, and is perceived 

 in the form of moisture. Thus we have a cold, damp air— the 

 very worst air for the health. I never walk through or even 

 cross a salted street, without having my cough increased, and I 

 have no doubt that every such exposure must tend to shorteil my 

 days. 



Dr. Gardiner. — The first question, to be decided in relation to 

 this matter is, whether it is desirable to have the suow removed 

 from the streets. In Paris and other cities in France, when the 

 snow falls to the depth of a few inches, a large number of work- 

 men are employed with carts, and in a short time the snow is all 

 carted away. There is so little snow in that country that it is 

 not used for sleighing, and when it does fall it is simply a nuis- 

 ance, to be got rid of as soon as possible. But the case is differ- 

 ent with us. The country around New York is frequently so 

 covered with snow, that the roads are impassable with wheeled 

 vehicles, and if people visit the city at all, they must use sleighs 

 or sleds. If the snow is all removed from the streets, they can- 

 not be traversed with runners, and the country people find it 

 impossible to get about with their sleds. Now, it is a question 

 worthy of consideration, whether the streets of the city should 

 not be adapted to the same vehicles as the roads in the vicinity. 

 Cut off the city from the country, and the city perishes. 



The Chairman. — I invited Dr. Sayre to be present at this dis- 

 cussion, and to give us his views. He is the city physician, and 

 in his official capacity caused the practice to be discontinued. 

 He has devoted a great deal of attention to the subject, and can 

 doubtless give us some pertinent facts in relation to it. 



Dr. Sayre. — Mr. Chairman, I thank you for the invitation to bo 

 present at this discussion. Dr. Gardiner, Mr. Smith and Mr. 

 Dibben have so fully stated the chemistry and science of the 

 matter, that it is not nepessary to go into that branch of the sub- 

 ject. Every old woman knows that if she mixes snow and salt 

 together, and sets her vessel of prepared milk and eggs into the 



