48 JOLY AND MUSSEYj ON HETEROGENESIS. 



experiments^ continued uninterruptedly for six months, they 

 are prepared with fresh evidence in the cause now at issue 

 between the partisans and the opponents of heter agenesis. 



As, in fact, the cardinal point of the question is reduced to 

 the means we may have of obtaining air of extreme purity, 

 that is to say, completely deprived of the germs Avhicli are 

 said to float in the atmosphere, they conceived the idea of 

 experimenting with the air or gas contained in the closed 

 cavities of organized bodies. The swimming-bladder of 

 fishes, the fruit of the bladder-nut, the fruit of the piment 

 annuel, the enormous cavity in the culinary Cucurbitaceae, 

 &c., aflForded, as it may be said, exactly what was desired. 

 They then proceed- to detail the results of an experiment of 

 this kind made with the Pumpkin. 



They boiled for two hours in distilled water some pieces of 

 sheep's liver. They then took a tube, blown into a pear- 

 shaped bulb at one extremity, open and drawn out at the 

 other. This tube was heated for half an houi', until the glass 

 was softened, and at this moment the open end was hermeti- 

 cally closed with the blowpipe. When cold, the point is 

 plunged into the boiling decoction and broken off below the 

 surface. A portion of the fluid enters the tube, which is 

 immediately placed on burning charcoal. Ebullition recom- 

 mences, and the tube is again closed whilst the steam is 

 escaping. The continuance of the ebullition, sometimes for 

 more than a quarter of an hour after the removal of the tube 

 from the fire, shows that the vacuum is as perfect as possible. 

 When the apparatus is cooled, the point of the tube is inserted 

 in the flesh of the gourd, and broken ofi" after it has entered 

 some distance. On its reaching the cavity of the fruit, a small 

 quantity of air enters the tube containing the decoction. In 

 order to take every possible precaution, a thick layer of copal 

 varnish, thickened with vermilion, was placed around the 

 wound made by the entrance of the tube. A criterion 

 apparatus was placed alongside, as a term of comparison. This 

 experiment, simple as it may appear, nevertheless presents 

 considerable difficulties in the performance. The authors 

 succeeded well twice, but made several other attempts in 

 vain ; being baffled sometimes by one cause, sometimes by 

 another. 



At the end of six days' attentive watching, they examined 

 the decoction, and perceived in it numer'ous Bacteria. INIany 

 were already dead, and the survivors in a languid condition ; 

 a very natural resiilt, if we consider, — 1, that the air contained 

 in the pumpkin abounds in carbonic acid, of which it holds 

 about four per cent. ; 2, that only a few buljbles of air entered 



