Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: in the Air into which they are emitted;- according to . 4 Obferv. 3. Obferv. 7. That the peftilential Particles emitted from the Body of a Perfon fick of the Plague, into the Air of the Room circumambient to him, are diffufed in it, and conveyed with that Air, whitherfoever it goes. . 6. Having made thefe Remarks concerning the peftilential Infeftion, I mould in the next Place confider the principal Ways by which it is conveyed thro’ the Air to human Bodies: But, for the better Under- ftanding this important Affair, I ihall pre- mife the following Obfervations. Obferv. 1. That there is commonly a Flux, or Current of Air, thro’ the Chimnies of Houfes: In fome Chimnies it is always upwards, but in others the Courfe of the Air is fometimes upwards, and fome- times downwards. Obferv. 2. That the Current of the Air in Chimnies is downwards, while the Smoke of the Fire is blown down into the Room, inftead of paffing upwards thro’ the Chimnies. Obferv. 3. That, while the Current of the Air in Chimnies is downwards, all Sorts of B 4 ParticlesParticles of Matter diffufed in the Air of the Atmofphere near the Tops of fuch Chimnies, and which by the Motion of the Wind are brought to them, will, with the Air, pafs down fuch Chimnies into the Houfes: And therefore by this Way pefti- lential Infeclion may be brought into Families, when a City is vifited with the Plague; as I fhall fhew hereafter. Obferv. 4. That the Making a Fire in the Chimney of a Room forces the Current of the Air thro’ it to be upwards, except it be fuch a Chimney as throws down the Smoke into the Room: And, as the Fire is greater or leffer, fo the Current of the Air up thro the Chimney will be quicker and ftronger, or flower and weaker. . 7. This is evident from the Effect of Fire on the S…
