276 M. H. Hoffmann on Fomentation, 



decomposing liquids containing sugar, and evolving gas, or, with 

 the addition of oxygen, of causing the corruption and putrefac- 

 tion of other organic liquids, then, by protecting these liquids 

 from the Fungi, we should be able to preserve them in an incor- 

 ruptible state. On this point Schroder has made a series of re- 

 markable experiments, from which it appears that the dust of the 

 atmosphere is in almost all cases the cause of the decomposition 

 of organic liquids which have been boiled. He has, however, 

 half abandoned the suspicion which he entertained that the 

 spores of Fungi played an important part in this, on observing 

 that when the liquids had been heated the spores no longer 

 induced decomposition ; and he has arrived at the result that the 

 dust only produces this effect when the materials have been pre- 

 viously in contact with the free air. M. Hoffmann, on the con- 

 trary, believes that decomposition may be produced by means of 

 the spores of Mucedinece (supposing that they are not killed 

 thereby), by placing them for an hour in the midst of liquids 

 heated to 214° F. 



Organic liquids, such as broth, saccharine solutions, glue- 

 water, boiled apples, honey and water, &c. placed in test-tubes 

 well closed with a cotton plug, and boiled for an hour, remained 

 intact for three to eight months, notwithstanding the excessive 

 heat of the summer of 1859. But the result of the following 

 experiment was very different : — Before pushing in the plug of 

 cotton, an iron wire of moderate strength was passed through 

 it ; to the lower extremity of this was attached a small glass 

 tube, two inches long, closed at both ends, containing dry spores 

 of the Fungus on which the experiment was to be made. A 

 second iron wire, placed by the side of the former, was attached 

 to the lower part of the small tube ; when the liquid in the test- 

 tube had been boiled, and become cool, this served to break the 

 two extremities of the small enclosed tube, and thus place the 

 spores in contact with the liquid surrounding them. If these 

 spores belonged to Penicillium glaucum, they rose to the surface, 

 and in a few days covered it with a thick carpet of Penicillium. 

 With the spores of Ustilago carbo and Stachylidium pulchrum, 

 or dried beer-yeast, fermentation does not occur, or is produced 

 very feebly, because the dried spores rise and float on the sur- 

 face. If, in place of a small closed tube, an open tube be em- 

 ployed, the boiling vapour alone is sufficient to kill the spores, 

 and in this case the liquid undergoes no alteration. Thus, 

 although such experiments cannot be performed without some 

 of the spores contained in the atmospheric dust arriving at the 

 liquid, they would be killed by the boiling. 



It has long been known that the dust of inhabited houses 

 contains spores. If an organic liquid which has been boiled be 



