v] of Chemical Physiology. 135 



" of wine in the must ; but negative experiments shewed me 

 "that the gas of grapes and must was preparatory to the 

 " wine but not the spirit of wine (alcohol) itself. 



"The history of gas is well shewn by gunpowder, which 

 "consists of saltpetre, sulphur and charcoal. When these are 

 " mixed together and ignited there is no vessel in nature which 

 " (if these were shut up in it) would not, on account of the gas 

 " produced, burst." 



His gas he affirms is not air. " Some impostors think that 

 " gas is wind or air occluded in things, having been introduced 

 "into the mixture of elements at the origin of things." But 

 this is not so. Gas is really a form of water. " The gas 

 " of salts is water. That the gas of fruits is nothing but water 

 " follows from what I have already shewn, namely, that these arise 

 " from water. A dried grape, submitted to distillation, is thereby 

 " reduced by art to elemental water, whereas a grape fresh but 

 " injured gives rise to must and gas. Since therefore the whole 

 "grape in the absence ot ; ferment is turned into water, but 

 " gives rise to gas whenever a ferment is applied, it follows of 

 " necessity that the gas is itself water." 



Deeply impressed with this idea of the action of ferments, 

 van Helmont makes it the basis of his system of physiology. 

 Nearly all the writers before him had caught hold of the pheno- 

 mena of the fermenting wine-vat, as being, though mysterious 

 in themselves, illustrative of the still more mysterious pheno- 

 mena of the living body ; and the old idea of the physiological 

 spirits of the body, natural, vital and animal, was connected in 

 its origin with this same formation of alcohol, of spirits of wine 

 by fermentation. The anatomical school of Vesalius and those 

 after him, busy with other things, did not attempt to develope 

 the conception ; they, as we have seen, passed on one side of the 

 chemical events of the living body. Van Helmont was the first 

 to attempt a connected exposition of these matters. He was 

 doubtless well acquainted with the physiological and anatomical 

 teaching of the time. But in his writings he dwells very little 

 on these ; he is chiefly concerned with the chemical events 

 which others had neglected. 



His exposition of physiology is based on a theory of ferment- 



