INVESTIGATION AS TO ORIGIN OF CATTLE DISEASES. 177 



called culture apparatus were employed. This last was made as fol- 

 lows : 



lu a flat glass capsule, six iuclies iu diameter and one and a lialf iucli 

 high, is placed a porcelaiu 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 paraflin, through 

 which passes a tube bent and 

 packed with cotton, as in the 

 isolation apparatus. (Fig. 16.) 

 When in use the external space 

 between the bell-jar and the 

 capsule is filled with a strong 

 solution of permanganate 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 puri- 

 fies from foreign nmtters by 

 causing it to pass through FIG. 16 



alcohol or a solution of permanganate of potash. It seems to us 

 that this plan gives more complexity and trouble without additional 

 security, for we have repeatedly caused spores of various species of fungi 

 to germinate after they had been one or two minutes in alcohol ; and 

 spores being not easily wet by water, they would readily pass without 

 injury iu a bubble of air drawn through any aqueous solution. The risk 

 of spores passing through an inch of dry cotton loosely packed in a tube, 

 unless by the aid of a strong and long-continued current of air, is proba- 

 bly very small. 



Of course the most satisfactory proof of the presence of fungus germs 

 in the blood would be to see them actually develop under the microscope, 

 and produce the forms by which they could be identified. To this end 

 we have made use of the various forms of growing slides known to 

 microscopists, but with not very satistactory results. For the general 

 purposes of a growing slide, that which has given the most satisfaction 

 is made by laying on an ordinary glass slide, three inches by one, a piece 

 of thin, fine, white blotting ])aper of the same size, with an oi)eiiiug in 

 the center three-fourths of an inch iu diameter, or a little less tliau that 

 of tlie tliin glass cover used. The edges of the paper may be cemented 

 to the glass with a little Canada balsam, although this is not necessary. 

 12 



