572 FRAGMENTS OF SCIENCE. 



in such things, and apparently also as regards a large 

 portion of the medical profession, our clever countryman 

 succeeded in restoring the subject to a state of uncertainty 

 similar to that which followed the publication of Pouchet's 

 volume in 1859. 



It is desirable that this uncertainty should be removed 

 from all minds, and doubly desirable on practical grounds 

 that it should be removed from the minds of medical men. 

 In the present article, therefore, I propose discussing this 

 question face to face with some eminent and fair-minded 

 member of the medical profession who, as regards 

 spontaneous generation, entertains views adverse to mine. 

 Such a one it would be easy to name; but it is perhaps better 

 to rest in the impersonal. I shall therefore simply call 

 my proposed co-inquirer my friend. With him at my 

 side, I shall endeavor, to the best of my ability, so to con- 

 duct this discussion that he who runs may read and that 

 he who reads may understand. 



Let us begin at the beginning. I ask my friend to step 

 into the laboratory of the Eoyal Institution, where I place 

 before him a basin of thin turnip slices barely covered 

 with distilled water kept at a temperature of 130 degrees 

 Fahr. After digesting the turnip for 

 four or five hours we pour off the 

 liquid, boil it, filter it, and obtain an 

 infusion as clear as filtered drinking 

 water. We cool the infusion, test its 

 specific gravity, and find it to be 3006 

 or higher water being 1000. A 

 number of small clean empty flasks, 

 of the shape shown on the margin, 

 are before us. One of them is 

 slightly warmed with a spirit-lamp, 

 and its open end is then dipped into 

 turnip the infusion. The warmed 

 glass is afterward chilled, the air within the flasks cools, 

 contracts, and is followed in its contraction by the infusion. 

 Thus we get a small quantity of liquid into the flask. 

 We now heat this liquid carefully. Steam is produced, 

 which issues from the open neck, carrying the air of the 

 flask along with it. After a few seconds' ebullition, the 

 open neck is again plunged into the infusion. The steam 

 within the flask condenses, the liquid enters to supply its 



