REPORT ON MOSQUITOES. 59 



compartment. Here I found a colony of insects in a moist corner, near the 

 water-supply pipe. 



Before I relate the conditions prevailing in those cellars which were not 

 found infested by the insects I would like to say something about the habits 

 of the hibernating mosquitoes as they came under my notice. From the first 

 day of the hibernation up to the months of January and February the insects 

 are found on the walls of cellars, resting about from 6 to 18 inches from the 

 floor of the cellar. As the season advances the insects find their low quarters 

 uncomfortable. Their partly dormant vitality receives an impetus; they crawl 

 or fly to higher quarters (I have noticed them as high as five feet only three 

 weeks ago), where they remain until the warm rays of the sun urge them on 

 to leave their winter quarters, to come out to the open, to be fruitful and to 

 multiply. 



I will proceed now to give a description of the cellars where no insects were 

 found : 



Cellar number 18 is located on Hunterdon street. Dry atmosphere, large 

 stone foundation, thoroughly whitewashed, plain sand floor. This cellar was 

 extremely dark, not a ray of sunlight ever entering its interior. No possible 

 chance for a mosquito to enter. 



Cellar number 19 is located on Lentz avenue. Moist atmosphere, brick 

 foundation, walls whitewashed. I have no doubt that I would have found 

 mosquitoes in this cellar, but the owner of the house conducts a butter and 

 egg business, and it was his custom to leave the cellar door open during the- 

 winter, rendering the place a very cold one. 



Cellar number 20 is situated on Gillet place. Dry cellar, floor cemented, 

 brick walls, whitewashed, fairly good ventilation. 



Cellar number 21 is located in Lyons Farms. Despite the assertion of the 

 owner that mosquitoes would be found there in numbers, a thorough search 

 produced a negative result. The cellar, from a sanitary standpoint of view, 

 was immaculate. Floors cemented, large stones were used in the building of 

 the foundation, thoroughly whitewashed, not a particle of moisture noticeable. 



Cellar number 22 is located on West Kinney street. Very dry, fairly good 

 ventilation, brick foundation, whitewashed, floor cemented. Cellar used for 

 the storage of malt liquors. 



Cellar number 2Z is located on West street. Very damp, poor ventilation, 

 brick foundation, partly whitewashed. This cellar appeared to be a good 

 hibernating quarter for the insects, but close examination proved the negative. 

 This cellar is also used for the storage of malt liquors. 



Cellar number 24 is located on Monmouth street. This cellar was the vilest 

 and most unsanitary I ever saw. Brick foundation, not whitewashed, plain 

 sand floor, water in certain places three and four inches deep, and a leaky fur- 

 nace expelling carbon monoxide added to this unsanitary condition. Malt 

 liquors and carbonated beverages were stored here. In a general summing 

 up of these last-named cellars, numbered respectively 22, 23 and 24, I account 

 for the absence of the insects by the large quantity of carbonic acid gas present. 

 A precipitating vessel filled with baryta water, placed at the height of 10 

 inches from the floor, reacted in 2 minutes, showing an unusual amount of 

 carbonic acid gas present in these cellars. This gas being more than half as 

 heavy again as air, its weight being 1,529, it will be found in more or less of 

 a layer, according to the depth of the cellar or the ventilation, wherever fer- 

 menting liquids are kept. The gas is irrespirable in a concentrated form, but 

 found mixed with air to the extent 5 to 7 per cent., as is the case in the afore- 

 named cellars, it acts as a narcotic poison, not alone to the human organism, 

 but the animal organism as well. 



Having thus given a description of where and how I found the hibernating- 

 insects, I proceed to the second part of my investigation, to wit: Kxperiiiients 

 to find a practical method to destroy the hibernating mosquitoes. A good 

 many materials have been tried to destroy the insects liy means of fumigation, 

 but either the material was found not to produce the desired effect or it 

 bleached fabrics, corroded metal, etc., not to speak of some the use of v. Inch 

 might result fatally to the operator. After a few weeks of experimenting I 



