I could yet give a much larger Account of Animals and Plants, how they have been particularly Infected, but I rather choose to refer my Reader to the Chapter at large, of Blights and Plagues, in my New Improvements of Planting and Gardening, &c.
By the foregoing Accounts we may observe, that Mankind, Quadrupedes and Plants seem to be infected in the same manner, by unwholesome Insects; only allowing this Difference, that the same Insect which is poisonous to Man, is not so to other Animals or Plants, and so on the contrary; we observe likewise, that Pepper which is of Use to Mankind, is poisonous to other Creatures, and tho’ a Man cannot eat of the Cicuta, or Hemlock, without prejudice, yet a Cow and some other Animals will eat it to their Advantage; and the Manchanese Apple, which is deadly Poison to almost every Creature, is eaten greedily by Goats, and which is strange, the Milk of those Goats is wholesome to Mankind. Again, we may remark that Camphire which may be taken at the Mouth by the Human Race, and is helpful in many Cases, will destroy Insects; for among the Curious who have Cabinets of Rarities, it is a common Practice to lay it in their Drawers and Cases, to destroy the smaller kind of Insects, which would otherwise devour their Collections.
The Smoaking of Tobacco is helpful to some Constitutions, but was the pure Leaf to be taken directly into the Stomach, it would Purge in a violent Manner, and the Oil of it as I am told is a deadly Poison; however it is to be remarked, that in the time of the last Plague in London, Anno 1665, that Distemper did not reach those who smoak’d Tobacco every Day, but particularly it was judged the best to smoak in a Morning. We have an Account of a famous Physician, who in the Pestilential time took every Morning a Cordial to guard his Stomach, and after that a Pipe or two before he went to visit his Patients; at the same time we are told, he had an Issue in his Arm, by which, when it begun to smart, he knew he had received some Infection, (as he says) and then had recourse to his Cordial and his Pipe, by this means only he preserved himself, as several others did at that time by the same Method. I suppose therefore, that the Smoak of Tobacco is noxious to these Venomous Insects, which I believe to be the Cause of the Plague, either by mixing it self with the Air and there destroying them, or else by provoking the Stomach to discharge it self of those Morbid Juices which would nourish and encourage them.
When I consider that the dead Bodies of the miserable People of Marseilles were found full of Insects, and that those Worms could be no way so suddenly killed, as by putting Oil or Lemon Juice upon them, it brings to my Mind several Tryals I have made upon Insects of various Kinds, in order to occasion their speedy Death. In these Experiments, I found that most of the larger Kinds would live some Minutes in Spirit of Wine and other spirituous Liquors, when they were forced into them, and that Oil immediately suffocated them, from whence I suppose, the Air, or Breath they draw, is exceeding fine and subtile, and that a thick Air consists of too gross Parts for them to breath, and that since Oil destroys the larger Kinds of them immediately, the Oleagenous Particles evaporating from such Bodies as Oil, Pitch, Tar, &c. expanding themselves, and mixing with the common Air, would render it too thick for the smaller Kinds to subsist in.
We observe likewise that all Aromatick Herbs, &c. were found useful in the time of the dreadful Pestilence in 1665, which helps to confirm what I have just now related, for a single Leaf of Rosemary contains at least 500 little Bladders of Oily Juice, which by rubbing, break and afford that grateful Smell we find in that Plant, but in that as in all other Aromatick Herbs, was we to bruise the Leaves ’till all those Bladders were broken, the recreating Smell would be lost, and we should find only remaining an earthy, disagreeable Flavour, arising from the common undigested Sap; so if we take the Leaves of Fifty several Kinds of Aromatick Plants, and after bruising them, make up distinctly the bruis’d Leaves of each into Balls, and dry them by the Sun, or otherwise, they will all afford the same Smell; for the breaking of those Bladders, or Blisters, which yield the different Smells (from the Essence they severally contain) makes them lose all their Spirit or Essence.
In the Culture of these Aromatick Herbs, such as Rosemary, Lavender, Thyme, &c. we may remark, that they are never destroy’d by any Insect, which may still give us a further Proof of the Antipathy all Insects have to them, for which Reason some People are used to smoak their Houses with these Aromatick Herbs, but especially where the Chambers or Rooms are small and close; and it has been proved, that the Burning of Aromatick Gums and Woods, have likewise been useful in purifying the Air in a House, and preventing the Spreading of Pestilential Distempers.
In 1665 it was observable, that in Aldermanbury, and other Places, where there were large Ware-Houses of Aromatick Druggs, the Infection did not reach; so that it seems where there is Quantity enough of such Woods or Gums, as yield a strong Smell, we have no Occasion of burning them, the bare Effluvia rising from a large Mass, having the same Effect as burning a small Quantity. As every one of these Druggs, or Gums, is more pungent or operative upon the Organs of Smelling, so we may be assured, the Vapour proceeding from them fill a larger Space in the Air; but perhaps a Tun Weight of the strongest Aromatick among them, in the Body or Mass, will not purifie so much Air as half an Ounce of the same will do by burning; for the Smoak of a few Grains of Tobacco, when the Air is clear, will sensibly touch the Smell above forty Yards, tho’ a Pound of the Herb unburnt will not affect the Smell above a Foot.
These Observations may serve to inform us, that the burning of Aromaticks may help to keep the Air in an healthful State; but as Men of Business must often change their Station, and pass thro’ different Degrees and Tempers of Air, it is for that Reason, that Aromaticks, and strong smelling Roots, Herbs, &c. are recommended to be taken into the Stomach. The Cordial which we call Plague-water, compos’d of Aromatick Herbs, has been used with Success, as has also been Conserves of Rhue, &c. and the Use of Garlick in the Amiens Distemper, particularly, is remarkable. To this I may likewise add a Relation I had lately from some Men of Quality concerning a Plague, which some Years since destroy’d a great part of the French Army: It was observable, that at that time the Irish Regiments in that Service were preserv’d by rubbing their Bread every Morning with Garlick, which undoubtedly must taint their Breath for many Hours, and so regulate the Air about them, that the unwholesome Insects could not approach them.
Upon this Occasion, I cannot omit observing the extraordinary Remedy for destroying the Insect call’d the Wevil in Corn or Malt, as it was communicated to me by the Learned Dr. Bentley, Master of Trinity College, Cambridge; that worthy Gentleman tells me, that the Herb Parietaria, or Peletory of the Wall, is a Sovereign Remedy against the Wevil in Corn or Malt; and according to the Information he has had, an Handful of that Plant being laid here and there in a Granary infected by those Insects, will infallibly destroy them in a Day or two; which Discovery is so useful, that I think it ought to be made as publick as possible, and in this place serves to confirm my Hypothesis, That the Effluvia of some Plants are Destructive to Insects.
In the next place I come to consider, how much a certain Quantity of Air is requisite to preserve a single Animal Body, and the Knowledge of that, is what I account one of the chief Preservatives of Health. I have often been concern’d to find a Family of six or seven pinn’d up in a Room, that has not contain’d Air enough for the Maintenance of Health in one single Person; but such is the Hardship of our Poor in many Places, and is frequently the Occasion of their Death.