28 



Description of a " Growing Slide " for Minute Organisms, 

 Constructed by Julien Deby, C.E., &c. 



Communicated by J. E. Ingpen, F.R.M.S., Hon. Secretary, 

 November 28th, 1879. 



PLATE II. 



This slide is illustrated at Figs. 5 and 6 in Plate II., Fig. 5 

 being a plan view and Fig. 6 a longitudinal section. In these 

 figures, A is a 3x1 glass slip, having a glass ring cemented to 

 it, so as to form a cell of about -J-in. deep and |-in. in diameter. A 

 small hole is bored through the slip at o, inside and near the edge 

 of the cell. The objects, such as bacteria, &c., are placed with a 

 very minute drop of water on a thin glass cover B, which is 

 attached to the top of the cell by a little lard. The slip is then 

 laid upon another of the same size, but not perforated, and a couple 

 of india-rubber bands h are passed over the ends. One end of 

 this arrangement is then placed in a little water, which, by capillary 

 attraction, will occupy the S23ace between the two slips, and, by 

 evaporation, will ^rise into the cell and prevent the minute drop of 

 water on the glass cover from drying up. By this contrivance, 

 a drop of water no larger than a pin's head can be kept of nearly 

 the same size for weeks together, and the development of bacteria 

 or other minute organisms kept constantly under observation. 



