Nay more! This West London efflorescence does not lie blooming alone. It is by no means the last rose of summer. On the east side of the great city, another, a rival upas-tree, spreads its nauseating blight. This is a mess that, oozing from a soap factory near Stratford-atte-Bow, envelops in its oleaginous cloud several hundred yards of the main line of the Great Eastern Railway. And the world we live in is so arranged that the trains, particularly in summer, are held up by signal for several minutes in this neighbourhood, so that, as the greasy slabs of decomposing fats slump in at the open carriage windows, an early opportunity is afforded to our Continental visitors of becoming acquainted with the purifying properties of English soap.

I am blushing now for what I have been saying about Ireland, Cologne, Lucerne, France, and even the East.

This last instance, however, opens up a large subject, that, namely, of malodorous industries. Of these there is a great number, too great indeed for me to do more than make a passing allusion to them. The proximity of evil-smelling works and factories to human habitations is, as a matter of fact, prohibited by the Public Health Acts, but it is naturally impossible to remove them entirely from the knowledge of mankind inasmuch as the workers frequently carry the atmosphere about with them. Fortunately for them, but unfortunately for us, by reason of the rapid exhaustion of the olfactory sense (which we are about to deal with in the following section), they are, for the most part, not incommoded by the objectionable airs they work in.

Perhaps the worst of all are the bone-manure factories, malodorous mills which are almost invariably situated at a distance of several miles from any dwelling-house, as it would be impossible for any one but the workers themselves to live in their neighbourhood. These unfortunate people, many of whom are women, carry, as I have already remarked, the stench about with them on their clothing and persons, and I have observed that, being themselves insensitive to the odour, they cannot rid themselves of it even on Sundays and holidays.

In this class also we must place tanneries, glueworks, and size factories, a visit to which is a severe trial for any one unaccustomed to them. Dyeworks, likewise, by reason of the organic sulphur compounds they disseminate through the spongy air, are unpleasant neighbours. In cotton mills, also, the sizing-rooms are objectionable, and here, curiously enough, the operatives do not seem to become accustomed to the smell, as it is insinuatingly rather than bluntly offensive, and grows worse with use. So much so, indeed, that but few of the girls, I am told, are able to remain in that particular occupation for more than a few weeks at a time.

At this stage, albeit early in our disquisition, we may appropriately turn to consider the curious fact that of all our senses that of smell is perhaps the most easily exhausted. The olfactory organ, under the continued stimulation of one particular odour, quite quickly becomes insensitive to it. Perhaps this is the reason, or one of the reasons, why reform was so long delayed.

There are, however, in this respect great differences between odours. With some the smell is lost in a few seconds, while with others we continue to be aware of it for a much longer time. Curiously enough, odours seem, in this matter, to follow the general law of the feelings in that the pleasant are lost sooner than the unpleasant. It is the first breath of the rose that makes the fullest appeal, when the whole being becomes for a moment suffused with the loveliest of all perfumes. But only for a moment. All too soon the door of heaven closes and the richness thins away into the common airs of this our lower world.

On the other hand, the aversion we all feel from substances like iodoform, or, what is worse, scatol, owes not the least part of its strength to the fact that both of those vile smells are very persistent. As was once said to a surgeon applying iodoform to a wound in a patient’s nose: “This patient will certainly visit you again, sir, but—it will not be to consult you!”

To this more or less rapid exhaustion of the sense is due the merciful dispensation that no one is aware of his own particular aura. We are only cognisant of odours that are strange to us. The Chinese and Japanese find the neighbourhood of Europeans highly objectionable, and we return the compliment. It is the stranger to the Island who remarks the “very ancient and fish-like smell.”

Fatigue and then exhaustion of a sense-organ, rendering it finally irresponsive to a particular stimulus, is, of course, familiar to us also in the case of vision, as the soap advertisement of our boyhood with its complementary colours taught us. Taste manifests the same phenomenon, for which reason (so he says) the cheese-taster in Scotland swallows a little whisky after each of the different samples he tries. But, curiously enough, the healthy ear is not thus dulled save by a very loud, persistent noise, and then there is the risk of permanent damage to the hearing organ. Some forms of tactile sensation, also, would seem to remain ever sensitive, for, although it may be possible to become so inured to pain as to ignore it, yet that is probably a mental act, and it is said, moreover, that men have been tortured to death by the tickling of the soles of their feet.