AND MARSHY SrrUATIONS. 



129 



iefs calcareous and argilaceous earth, and by diftillation 

 affords oil, hydrogen, and azote. 



From this foil, and from the various vegetable and 

 animal fublhinces mixed with it, and conflantly putre- 

 fying in hot weather, it has been fuppofed miafmata 

 illue, which give origin to the difeafes peculiar to marfliy 

 fituations ; and as there are no fubftances but thofe gafes, 

 already enumerated, which can be dilcovered to iffue 

 from a marihy foil, or from putrefying vegetable or ani- 

 mal fubftances, if thofe difeafes depend upon miafmata 

 or effluvia, thefe miafmata mull: confift of one or more 

 of the gafes enumerated.* 



In order to determine this matter, it will be neceflary 

 to enquire into the effed:s which thefe fubftances, ftngly, 

 or combined, ufually produce on the living human 

 body. 



If the carbonic gas or fixed air, when applied in a cer- 

 tain quiintity or in a concentrated ftatc, deftroys life in- 

 ftantly by its adion on the irritability of the mufcular 

 fibres of the heart, as from the obfervations of Mefli-s 



* " In the vinous fermentation, part of the principles of the vegetable 

 fubRance, viz. the hyJrogtn, remains united with a portion of water and 

 of carbon to form the alkohol. 



" In the acetous fermentation, a union takes place between the oxygen and 

 the alk.ihol, and earth) matter is depofited. In other words the bafe of 

 the pure air abforbed, uniting with the alkohol of the liquor, and tlie ef- 

 fential falts diifulved in it, terms vinegar, while a depofitii'n takes place of 

 earthy f-r oilv matters no longer foluble in the liquor. Hence vinegar is 

 in an intermediaie ftate between wine and fixed air, accordingly vinegar 

 may be nade by impregnating alkohol and wa:er with fixed air. 



" The gas of fermenting liqu rs which i-. fixed air, holding fome fpirit of 

 wine in folution received into w.jtet, has the fame efiieft. 



" In the pu-: id fermentiJtir'n ( u hich ;s the I'nly ipecies that takes place in 

 marlh-s,) the whole of the hydrogen is diffip.ited, under the form of in- 

 flammable gas, while the iixyg' n a d il'.e carbon uniting, w"ith the caloric 

 or principle of heat, efcapes unoer the i. tm of fixed -dr," after this prr. 

 ceis, if there has been fuftici ni vat.'-- and heat to C'mp'e-e 'he putrefactive 

 procefs, nothing remains but the eanh of the vegetable, mixed with a little 

 carbon and iron. Chaptaf. 



Prieftlev, 



