27 
It is to be noted that the explosion which occurred was not violent in any case. 
The strongest explosions occurred with mixtures containing from 20 to 60 volumes 
of air saturated with carbon bisulphid vapor at 72° F. mixed with 80 to 40 volumes, 
respectively, of pure air at the same temperature. 
In the second series of experiments a smaller proportion of carbon bisulphid was 
used in three cases. Five experiments were made. The capacity of 5 bottles hold- 
ing 4 liters (about 4 quarts) was obtained with approximate accuracy. For the 
charging of each bottle the quantity of liquid carbon bisulphid named in the follow- 
ing table was weighed in a small glass-stoppered weighing bottle. A string was tied 
to the stopper of the weighing bottle, which was then placed in the 4-liter bottle pre- 
pared to receive it. When the weighing bottle had reached the bottom of the large 
bottle, the stopper was removed by a sudden jerk of the string, the string was dropped 
in the large bottle, and it was quickly closed, the stopper being sealed in immedi- 
ately with paraffin. This method of preparing the mixtures is more accurate than 
the one employed for the first series of experiments. The 5 bottles thus charged 
were allowed to stand for about three hours for the thorough diffusion of the vapor. 
At about the middle of this period the bottles were inverted in order to facilitate the 
diffusion. The stopper of each bottle was then carefully removed and a small gag 
jet burning at the end of a glass tube wasinserted in the bottle. The results obtained 
are indicated in the following table: 
Inflammability of mixtures of CS, with the air. 
nn ee ee ee ee eee 


Wt. CS, per 
— ipa cla 1,000 cubie Inflammability. 
7 3 feet. 
ee ee ee ee ee 
Grams. Pounds. 
1 0. 0075 0.47 | Not inflammable; slight odor of sulphur dioxid after removal of gas 
jet. 
2 . 0182 1.14 | No general combustion; a very small blue mantle of burning carbon 
bisulphid formed around the gas jet. 
3 . 0461 2.88 | No general combustion; blue mantle of burning carbon bisulphid 
formed around gas jet. 
4 . 0805 5.02 | Inflammable. 
5 - 1552 9.68 | Very inflammable; very slight explosion. 


ee 
There was no general combustion except in the case of bottles Nos. 4and 5. In 
the case of bottles Nos. 3 and 4 the result was very interesting. The mixture of the 
vapor with air was so dilute that the small gas jet introduced did not heat it hot 
enough to cause a general combustion, but a zone of combustion extended around 
the gas jet in every direction in the form of a blue mantle. It is worthy of note 
that the proportion of carbon bisulphid used in No. 3 (2.88 pounds per 1,000 cubic 
feet) is more than is ordinarily used in the fumigation of buildings. It must be 
remembered, however, that when small proportions of carbon bisulphid are used, 
the quantity in the air near the vessel containing it may be sufficient to cause an 
explosion if a flame is brought near it, or if the mixture be sufficiently heated by 
any other means. 
The experiments reported above were made with chemically pure carbon bisulphid. 
The third series of experiments described below was made with the commercial car- 
bon bisulphid known in the market as ‘‘fuma,’’ which is largely used as an insecti- 
cide. As a comparison of the results will show, the inflammability of this commercial 
grade of carbon bisulphid is not essentially different from that of the chemically pure 
substance. 
