182 Dr. G. Child on the Production of [Apr. 27, 



have here a series of ten experiments instituted with a view of showing 

 whether organisms can be produced in vegetable infusions within closed 

 vessels supplied with heated air. In my desire to try a variety of sub- 

 stances I took almost anything which my garden afforded, and in this way 

 probably my selection of sage and celery may have been a bad one, as the 

 aromatic ingredients of these plants may be supposed to influence the 

 result of the experiment, especially as in a close vessel any volatile oil 

 would be retained. If, therefore, the three experiments with these sub- 

 stances be eliminated, there remain seven experiments, one with pea-meal, 

 two with hay, and four with coarse flour. Of these, five were examined on 

 Sept. 19, and in three (viz. the pea-meal and the two hay experiments) the 

 vessels were found to contain moving organisms. In two (those performed 

 with coarse flour) none were found, and in the remaining two, examined on 

 Nov. 16, also none were found. 



In the meantime, when, from several of the above experiments having 

 produced negative results, I looked upon tlie series as inconclusive, I 

 instituted a fresh series of twelve experiments in the end of September, as 

 follows. 



The apparatus employed was the same as that used in the last series, 

 except that I had some large double bulbs made for the present series. In 

 other respects the process was the same as before. 

 Exp. I. Sept 30. Hay infused 31 hours in water, filtered, and boiled 



10 minutes in a stream of heated air sealed up when cool. 

 Exp. II. Sept. 30. Similar in all respects. 

 Exp. III. Oct. 1. Similar. 

 Exp. IV. Oct. 1 .Similar. 

 Exp. V. Oct. 5. Flour infused in warm water 3-^ hours and filtered : 



boiled 11 minutes, as before, and sealed. 

 Exp. VI. Oct. 5. Similar: boiled 10 minutes. 

 Exp. VII. Oct. 5. A similar infusion infused 6^ hours, not filtered : 



boiled 10 minutes. 

 Exp. VIII. Oct. 5. Similar. 

 Exp. IX. Oct. 7. Flour infused 3^ hours, not filtered : boiled 10 minutes 



in a stream of oxygen, and sealed as before. 

 Exp. X. Oct. 7. Similar: boiled 10^- minutes. 

 Exp. XL Oct. 7. Flour infused 4^ hours and filtered: boiled 10 minutes 



in oxygen. 

 Exp. XII. Similar. 



On Oct. 8 this series of experiments was divided into two sets : [B], 

 Nos. II., IV., VI., VIII., X., XII., were placed on a high shelf in my 

 dining-room ; the rest [A] in a hot closet, by the side of the cooking-stove, 

 in the kitchen. 



The object of the latter arrangement was to ensure the vessels being 

 kept warm enough during the winter months ; but the heat was, I have 

 no doubt, too great. I saw the thermometer on more than one occa. 



