Chapter III 



29 — 



Collecting Samples at Sea 



activated breaking mechanism which can be used for either citrate of 

 magnesia bottles or collapsible rubber bottles. The former can be used to 

 a depth of 200 meters without danger of breakage by the water pressure. 

 Rubber bottles can be used to any depth in the sea. Both types of bot- 

 tles are fitted with a short piece of heavy-wall rubber tubing which is 

 closed by a piece of small-bore glass tubing hermetically sealed at the 

 end (see Fig. 3). 



The assembled J-Z bottles are sterilized by steam pressure. They are 

 sealed as soon as they are removed from the autoclave so that upon 

 cooling they shall remain partly evacuated. The resulting reduced pres- 

 sure facilitates the collection of samples. The rubber bottles are com- 

 pletely collapsed prior to sealing. 



An important innovation in the J-Z sampler is the piece of rubber 

 tubing, suggested by Schach (1938), which facilitates the construction 

 and adjustment of the capillary inlet tube. An assembled bottle is con- 



C 



tr=r=' 



^«/ 



E 



Fig. 2. — Types of capillary-tube water samplers used by Russell (A), 

 IssATCHEXKO (B), WiLSON (C), Gee (D), and ZoBell (E). The arrows 

 indicate the points where the tubes are broken by the breaking mechanisms 

 to permit the entrance of water. 



nected to the carrier as illustrated by Figure 3 . When the messenger en- 

 gages the lever, the latter strikes the glass tube, causing it to break at a 

 point of strain, FM, a tile mark. When the glass tube is broken, the rub- 

 ber tube straightens out so that the sample is taken from a position sev- 

 eral inches away from any point of contamination on the carrier or cable 

 to which it is attached. 



The carrier is adapted for ready connection to a standard hydrographic 

 wire or cable. Several of the J-Z bacteriological water samplers can be 

 connected seriatim on the cable as it descends into the water, thereby 

 making it possible to collect samples concurrently from several different 

 depths at the same station. When the messenger activates the uppermost 

 sampler on the line, it releases a second messenger which activates a sec- 

 ond sampler farther down the line. This releases the third messenger, 

 the third releases the fourth, and so on. The J-Z samplers can be used on 

 the same line with Nansen bottles, Allen bottles, reversing thermom- 

 eters, and other standard hydrographic apparatus. 



