Dr Stark on the Influence of Colour on Odours. 95 



emanations generally, are emitted on the one hand, and on the 

 '.i\\ev received, according to the same general laws. 



Experience has sufficiently proved, that emanations once ge- 

 /ierated in, or communicated to, the human body, may be con- 

 veyed from one individual to another, and even, through the 

 medium of clothing or merchandize, from one place to another. 

 This has been particularly observed in plague ; and hence in 

 countries where this disease is liable to occur or be imported, 

 the institution of quarantine establishments, to prevent personal 

 intercourse or the dispersion of goods, till a certain number 

 of days have elapsed, during which the disease, if existing, 

 should appear ; — articles of merchandize and clothing being at 

 the same time purified by exposure to the air, or fumigated. 

 Though this transport of disease has been more particularly ob- 

 served in plague, yet instances of the same nature have occurred 

 in other diseases, more particularly small-pox, and more re- 

 cently it has by many been supposed in cholera. 



It is unnecessary to detail the means of purifying infected 

 goods, or fumigating the apartments of those who have been 

 known or suspected to labour under diseases supposed to be 

 communicated by contagious effluvia. It is sufficient to state, 

 that exposure to a high temperature, fumigation with chlorine 

 and sulphur, and free exposure to the air, are found amply suf- 

 ficient for the first ; and apartments are more generally recom- 

 mended to be purified with chlorine, and washed with caustic 

 hme. As to fumigations with chlorine, it cannot be denied that 

 this will destroy the effluvium floating in the air exposed to its 

 action ; but unless this fumigation be frequently repeated, it can 

 have but little effect, as the walls and furniture will be con- 

 stantly contaminating the air, by giving out the deleterious par- 

 ticles which they had previously absorbed. Lime washing has 

 generally been supposed to act in the same manner as fumiga- 

 tions, viz. by destroying the contagious emanations ; but from 

 the experiments of Guy ton Morveau, it would seem that caustic 

 lime, and indeed lime in any state, has no such effect. It merely 

 absorbs the gases which disguise the odour, but neither changes 

 its deleterious properties nor alters its real smell. He, therefore, 

 disregards lime-washing, except as a general mode of cleaning 

 walls, and attributes no other beneficial effect to it than as con- 

 tributing to cleanliness. 



