Ether has a peculiar and very strong odour; in this respect it differs extremely from chloroform. The odour of a single drop of ether can be distinctly perceived all over a large operating theatre, whilst a pint of chloroform may be spilt without its odour being much noticed. The strong odour of ether is, indeed, one of the greatest objections to its use, since another agent has been discovered which is free from this objection. As was previously stated, the odour of chloroform cannot be perceived in the breath, after the lungs are emptied by one or two expirations of the vapour just taken in; whilst the smell of ether can be perceived in the breath for twenty-four, and sometimes for forty-eight, hours after the patient has inhaled it. The surgeon, and others who have been about the patient, also smell of the ether to a less degree. When a rabbit has been killed by the inhalation of ether, a starving cat will not eat its flesh even after it has been boiled; whereas the odour of chloroform cannot be perceived in the bodies of animals that have been killed by it.
If ether is exposed to atmospheric air by being kept a long time in a bottle but partly filled, it is apt to be decomposed into acetic acid and water.
The following Table shows the result of experiments which I made to ascertain the quantity of vapour of ether that 100 cubic inches of air will take up, when saturated with it, at various temperatures, the barometric pressure being 30 inches of mercury. The ether I employed in the experiments was washed, but not dried. It was, therefore, saturated with water, of which it contained one-tenth of its volume. It had a specific gravity of 0·735 at 60° Fahr., and it boiled at 98°.
| Temp. Fah. | Cubic inches of vapour. | Minims of ether. |
|---|---|---|
| 50° | 52 | 64 |
| 51 | 54 | 66 |
| 52 | 56 | 69 |
| 53 | 59 | 72 |
| 54 | 62 | 76 |
| 55 | 65 | 80 |
| 56 | 68 | 84 |
| 57 | 72 | 88 |
| 58 | 76 | 93 |
| 59 | 80 | 98 |
| 60 | 84 | 102 |
| 61 | 88 | 107 |
| 62 | 92 | 112 |
| 63 | 97 | 117 |
| 64 | 102 | 122 |
| 65 | 107 | 128 |
| 66 | 112 | 134 |
| 67 | 117 | 140 |
| 68 | 123 | 147 |
| 69 | 130 | 156 |
| 70 | 138 | 165 |
In the above Table the air is a constant quantity of 100 cubic inches, which becomes expanded to 152, and so on; but the following Table shows the quantity of vapour in 100 cubic inches of the saturated mixture of vapour and air at different temperatures:—
| Temp. Fah. | Air. | Vapour. |
|---|---|---|
| 40° | 73 | 27 |
| 42 | 72 | 28 |
| 44 | 70 | 30 |
| 46 | 69 | 31 |
| 48 | 67 | 33 |
| 50 | 66 | 34 |
| 52 | 64 | 36 |
| 54 | 62 | 38 |
| 56 | 60 | 40 |
| 58 | 57 | 43 |
| 60 | 54 | 46 |
| 62 | 52 | 48 |
| 64 | 49 | 51 |
| 66 | 47 | 53 |
| 68 | 45 | 55 |
| 70 | 42 | 58 |
| 72 | 40 | 60 |
| 74 | 37 | 63 |
| 76 | 34 | 66 |
| 78 | 32 | 68 |
| 80 | 29 | 71 |
The absorption of caloric during the evaporation of ether is much greater than during that of chloroform, owing both to the greater quantity of vapour it yields on account of its lower boiling point, and to the lower specific gravity of the vapour. The evaporation of ether from the bulb of a thermometer usually lowers the temperature nearly to zero of Fahrenheit. When the inhalation of ether was first commenced, the inhalers employed consisted generally of glass vases containing sponge, to afford a surface for the evaporation of the ether. Both glass and sponge being very indifferent conductors of caloric, the interior of the inhalers became much reduced in temperature, the evaporation of ether was very much checked, and the patient breathed air much colder than the freezing point of water, and containing very little of the vapour of ether. On this account, and through other defects in the inhalers, the patient was often very long in becoming insensible, and, in not a few cases, he did not become affected beyond a degree of excitement and inebriety.
To ensure the ether taking effect in a short time in every case, I made use of the conducting power of the metals, and the great capacity of water for caloric. The inhaler which I employed was made of plated copper, and was placed in two or three pints of water, of the ordinary temperature. The form of the inhaler was that of one which had been contrived by Mr. Julius Jeffries for the inhalation of aqueous vapour.[[159]] No sponge or bibulous paper, or other material, was used; and the air, before being inhaled, was made to pass over a considerable surface of ether by means of a spiral volute, soldered to the top of the inhaler, and reaching nearly to the bottom. The accompanying engraving shows the interior of the inhaler, on a scale of half the dimensions, the bottom being removed.
The Physiological Effects of Ether are essentially the same as those of chloroform. The various degrees of narcotism which I described in the earlier part of this work, when treating of chloroform, were first described by me when treating of ether in 1847, before chloroform was in use.[[160]] All the remarks which I made with respect to the manner in which age, strength or debility, and other circumstances, influence the action of chloroform, apply also in an equal degree to ether.