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A Deep-sea Bacteriological Water-bottle. 



By 

 Donald J. Matthews. 



Witli Four Figures in the Text, 



In the past, deep-sea water samples for bacteriological purposes have 

 been taken either by means of water-bottles provided with taps, and 

 so made that the sample came in contact with metal, or in evacuated 

 sterilized glass vessels drawn out to a fine point and sealed in the 

 flame. The water-bottle is difficult to sterilize on account of the taps, 

 and the results obtained are vitiated by the bactericidal action of 

 metals.* The sealed glass tube is free from these defects, but at 

 even moderate depths it is liable to collapse on the sudden change 

 of pressure when the end of the capillary portion is broken off. 



The water-bottle here described has none of these disadvantages, 

 and has been used by Mr. G. H. Drew down to depths of 800 fathoms 

 with complete success. It was designed and made at short notice, and 

 time did not allow of more than one hurried trial before packing for 

 shipment. Experience has shown since that many small alterations 

 might be made which would render it more convenient, though not 

 more accurate, in use ; but as no opportunity of making and testing 

 an improved model is likely to present itself in the near future, it is 

 here shown in its original form. 



The body of the water-bottle consists of a brass cylinder a of about 

 250 c.c. capacity, lined with a glass tube 5. It moves freely by means 

 of the guides c on the side frames d, which are made of brass rod and 

 connected by circular plates h and i. Above and below the central 

 cylinder are movable plates e and /, with recesses in which fit rubber 

 washers, shown by shading. The washer plates and cylinder are 

 pressed downwards by spiral springs m and n working against the fixed 

 plate g, and can be held up against this pressure by two rods, only one 

 of which, /, is shown in the section. The shorter rod, /, is fixed to the 

 upper washer plate by a thread and lock nut which allow of a small 

 vertical adjustment ; it can be held up against the spring m by a bent 

 lever bracketed on to the top plate (Fig. 3). The upper end of the 



* G, H. Drew on "The Precipitation of Calcium Carbonate in the Sea," etc. This 

 Journal, Vol. IX, p. 479. 



