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DEPARTMENT OF AGRICULTURE. 



lively conclusive. By no means known to us can a piece of lung be transferred from the 

 body of an animal to the interior of a glass flask without contact with the atmosphere and 

 with instruments, nor even with the more manageable blood can we be absolutely certain, 

 when we see its surface covered with mold, that the possibly single spore from which that 

 forest sprang must infallibly have been in the vein of the animal whence the blood was 

 drawn. It was felt, therefore, that to adopt at the outset extraordinary precautions against 

 the introduction of foreign spores would be more apt to lead to error than even taking 

 none at all. The method of comparison was therefore resorted to. 



Let us first see, we argued, whether, without taking special pains to prevent the 

 entrance of extraneous matters, the tissues and fluids of a diseased animal will produce 

 fungi which healthy tissues and fluids placed side by side with them will not. The appa 

 ratus employed consists of the following: 



1st. The so-called &quot;isolation apparatus.&quot; 



This consists of a thin flat -bottomed flask, of four to eight ounces capacity, closed by 

 a cork dipped in paraffine. Through the cork passes a glass 

 tube bent twice at right angles, reaching about two inches into 

 the flask, and having the external end loosely closed by a pled 

 get of dry cotton or jewelers wool. 



This is used in operating upon considerable quantities or 

 masses of material which are to remain undisturbed for several 

 days, weeks, or months. 



To follow out the changes which occur from day to day, 

 and especially to trace under the microscope the commencement 

 and progress of any fungous growth, growing slides of various 

 patterns, and the so-called culture apparatus, were employed. V.. 

 This last was made as follows: 



In a flat glass capsule, six inches in diameter and one and a half inch high, is placed 



a porcelain stand two inches high, on which is laid a 

 glass plate, which serves as a shelf to hold watch 

 glasses, growing slides, &c. In the capsule covering 

 the stand and plate stands a bell-jar, closed at the 

 top by a rubber cork or cork dipped in paraffine, 

 through which passes a tube bent and packed with 



cotton, as in the isolation apparatus. When in 

 use the external space between the bell-jar and the 

 capsule is filled with a strong solution of perman 

 ganate of potash. We thus obtain a moist chamber, 

 which, by means of a water bath, can be readily kept 

 at any desired temperature. 



The above -described forms of apparatus are 

 essentially those used by Hallier, but he provides for 

 drawing into the flask or bell-jar fresh air, which he 

 purifies from foreign matters by causing it to pass 

 through alcohol or a solution of permanganate of pot 

 ash. It seems to us that this plan gives more complexity and trouble without additional 



