547.4

REGIONS OF REACTION XI. THE EXPLOSION REGIONS NITROUS OXIDE-ETHER

VAPOUR-OXYGEN, AND NITROUS OXIDE-ETHER VAPOUR-AIR

BY

W. P. JORISSEN AND B. L. ONGKIEHONG.

The use of a mixture of nitrous oxide, ether vapour and oxygen as an anaesthetic for surgical operations has raised the question as to which mixtures would explode if brought into contact with a spark o r heated wire.

For this reason Professor J. H. Zaaijer (Leiden) has asked us to determine the explosion regions

N,O - (C,H,),O - 0, and N,O - (C,H,),O - air. The apparatus used was the same as that which had served for the

investigation of the explosion region H, - NH, - 0, (or air). l) The nitrous oxide was taken from a cylinder of liquid nitrous

oxide z, and transfered to a gas holder; another gas holder was

Fig. 1.

l) Rec. trav. chim. 45, 224 (1926). 2, Coxeter, London: lent to us by the University Hospital. XLV 40

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filled with oxygen (nitrogen content 4 %). Both were provided with three way taps. In order to make mixtures of ether vapour and nitrous oxide, one lead of the three way tap of the nitrous oxide gas holder was connected to the tap b of burette B. The third lead of the three way tap was connected to a wash-bottle containing ether and then to the vertical tube of tap a of burette A. On turning tap d 180" and tap b 90" to the left, one is able to measure in burette B the desired quantity of nitrous oxide saturated with ether vapour. In order to obtain the desired mixture of nitrous oxide and ether vapour it is necessary to dilute with nitrous oxide. For this purpose tap b is left as drawn in Fig. 1, tap a turned 90" to the right, and, by lowering the mercury in burette A, a certain quantity of nitrous oxide is ad- mitted to this burette. Now, by turning tap b again 90° to the left, the nitrous oxide is brought from burette A into burette B, and the gases are thoroughly mixed by passing the mixture several (eight) times from B to A and back again.

If it is desired to add oxygen the mixture is passed into B and A filled with mercury to the tap a. By means of the taps a and h the oxygen is measured into burette A, and then the mixing is affected as described above.

So that mixtures of oxygen and ether vapour, as well as oxygen alone, could be used the tube on the left of the tap h was provided with a three way tap, one of whose leads was connected directly, and the other through a wash-bottle containing ether, to the leads of the three way tap of the oxygen gas holder. Both the washdbottles used were placed in a thermostat ( 16O).

If oxygen has been brought into burette A by means of tap h and it is desired to add oxygen saturated with ether, the oxygen is trans- fered to burette B, the tube ab having first been filled with oxygen. The three way tap connected to h is first filled with oxygen saturated with ether by allowing the first quantity to escape through the tubes h a d, and then the oxygen saturated with ether is passed into burette A.

By using the three way taps of both gas holders it is possible to make all the desired mixtures of nitrous oxide, oxygen and ether vapour.

I.

1. Ether vapour - oxygen.

No inflammation with 1 .O, 1.4 and 1.6 % ether vapour, inflammation with 1.8 "/o (two exp.) and 2.0 % (two exp.). Lower limit: 1.7 % ether vapour, 98.3 % oxygen.

Inflammation with 36.0, 38.0 and 39.0 76 ether vapour, but not with 40.0 % (inflammation after a few sparks), 42, 44 and 46 %. Upper limit: 39.5 % ether vapour, 60.5 7% oxygen.

E x p 1 o s i o n r e g i o n e t h e r-o x y g e n-n i t r ou s oxide .

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2. Ether - nitrous oxide. No inflammation with 2.0 %, 3.0 and 3.6 %, inflammation with

4.0 % ether vapour. Lower limit: 3.8 % ether vapour, 96.2 % nitrous oxide.

Inflammation with 20, 22, 24, 25 and 25.4 % ether vapour, but not with 26.0 (two exp.), 30, 36, 40, 44 and 46 %. Upper limit: 25.7 % ether vapour, 74.3 % nitrous oxide.

3. 20 % oxygen: No inflammation with 1.0, 2.0 and 3.0 % ether

vapour (in the latter case inflammation by the second spark), inflam- mation with 3.4, 4.0 and 5.0 %. Lower limit: 20 % oxygen, 3.2 % ether vapour, 76.8 % nitrous oxide.

50 % oxygen: No inflammation with 2.0 % and 2.4 % ether vapour, inflammation with 3.0 and 4.0 %. Lower limit: 50 % oxygen, 2.7 % ether vapour, 47.3 % nitrous oxide.

80 % oxygen: No inflammation with 2.0 and 2.4 % ether vapour, inflammation with 3.0 and 4.0 %. Lower limit: 80 % oxygen, 2.7 % ether vapour, 17.3 % nitrous oxide.

60 % nitrous oxide: Inflammation with 26.0 % ether vapour (two exp.), but not with 27.0, 28 and 30 %. Upper limit: 60 % nitrous oxide, 26.5 % ether vapour, 13.5 % oxygen.

30 % nitrous oxide: Inflammation with 30.0, 32.0 and 34.0 $% ether vapour, but not with 34.4, 35.0, 36, 40 and 44 %. Upper limit: 30 % nitrous oxide, 34.2 % ether vapour, 35.8 % oxygen.

Ether - oxygen - nitrous oxide.

The explosion region is drawn in fig. 2, viz. ADCB. N20

Ether

Fig. 2.

11. E x p l o s i o n r e g i o n e t h e r v a p o u r - a i r - n i t r o u s o x i d e . 1. Ether vapour - air. No inflammation with 1.0 and 1.8 % (inflammation by the 3rd

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spark), inflammation with 2.0 % ether vapour. Lower limit: 1.9 % ether vapour, 98.1 % air.

Inflammation with 6.0, 6.4 and 7.0 % ether vapour, no inflammation with 7.4 % (inflammation by the 3rd spark), 8.0 % (two exp.) and 10 %. Upper limit: 7.2 % ether vapour and 92.8 $6 air.

2. 50 % nitrous oxide: No inflammation with 1.0 and 2.0 % (inflam-

mation by the 3rd spark), inflammation with 2.4, 3.0 and 4.0 % ether vapour. Lower limit: 50 % nitrous oxide, 2.2 % ether vapour, 47.8 % air.

50 % nitrous oxide: Inflammation with 10.0, 12.0 and 13.0 % ether vapour, but not with 13.4 % (inflammation by the 2nd spark), 14, 16, 18, 20 and 21 %. Upper limit: 50 % nitrous oxide, 13.2 % ether vapour, 36.8 % air.

20 % nitrous oxide: Inflammation with 8.0 and 9.0 % ether vapour, but not with 9.4 and 10.0 % (two exp.). Upper limit: 20 % nitrous oxide, 9.2 % ether vapour, 70.8 % air.

Ether vapour - air - nitrous oxide.

The explosion region is drawn in fig. 2, viz. ADCE. On adding air to the mixture of nitrous oxide, ether vapour and

oxygen, the line CB moves to the left, revolving round C, and finally coincides with the line CE.

That mixtures of nitrous oxide and ether vapour may be explosive, was to be expected, as explosive mixtures of that endothermic gas with hydrogen, ammonia, carbon oxide, cyanogen, phosphine and hydrogen sulphide have been observed ' ) .

When the spark is strong enough to start in nitrous oxide (without ether vapour) a reaction which propagates itself, the line AD will revolve round A, and cut the left side of the triangle.

111. T h e s y s t e m c h l o r of o r m -0 x y g en-ni t r o u s ox ide . As also mixtures of these three substances are being used for

narcosis we have investigated whether they may be explosive. The experiments have been made at a temperature of 14O.

No inflammation with 2, 4, 6, 8, 10, 12, 14 and 16 % and with saturated chloroform vapour (at 14O : 17.3 % ).

No inflammation with 2, 4, 6, 8, 10, 12, 14 and 16 % chloroform vapour or with saturated vapour.

Mixtures containing 10, 20, 30 and 50 % nitrous oxide, proved not to be explosive with 2, 4, 6, 8, 10, 12, 14 and 16 % chloroform vapour (the rest being oxygen).

Mixtures with 10, 20 and 30 % oxygen were found not to be explo-

chloroform - oxygen.

chloroform - nifrous oxide.

chloroform - oxygen - nifrous oxide.

~~

See Abegg's Handb. d. anorgan. Chem. 111, 3, 206. Some of these mixtures will be further investigated, for instance when mixed

with nitrogen and oxygen, and also experiments will be made with the endothermic nitric oxide. The mixtures containing nitric oxide and carbon disulphide should prove to be especially interesting.

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sive, when containing 2, 4, 6 , 8, 10, 12, 14 and 16 % chloroform vapour (the rest being nitrous oxide).

The system chloroform - oxygen - nitrous oxide appears to have no explosion region at ordinary temperatures.

The conclusions to be drawn from our experiments for the practice of anaesthetics during surgical operations and experiments relating to the use of the mixtures treated above will be communicated else- where.

These experiments have been carried out with financial aid from the “Hoogewerff-Fonds”.

L e i d e n, T h e University, The Inorganic Chemistry Lab., July 1926.

( R e p le 7 sept. 1926).