Chapter III 



COLLECTION AND EXAMINATION OF SAMPLES 



AT SEA 



One of the most difficult of the pecuHar problems of technic confront- 

 ing the marine bacteriologist is the collection of samples of sea water or 

 bottom deposits for analysis from any desired location or depth. There 

 are very few places in the world where samples uncontaminated by land 

 drainage can be obtained without the use of a boat, and it is often neces- 

 sary to travel considerable distance from land. A small boat necessitates 

 the special preservation and rapid transport of samples, while bacteri- 

 ological work at sea even on a boat large enough to provide laboratory 

 facilities is vicissitous to say the least. 



The collection of water samples : — Most of the hundred or more 

 bacteriological water samplers which have been described are suitable 

 only for collecting surface samples or samples from shallow depths. In 

 the latter category are bottles from which the stopper can be removed by 

 a string, spring, or messenger at the desired depth. Johnston (1892) 

 devised such an instrument with a glass-stoppered bottle fastened in a 

 weighted metal frame which was lowered to the desired depth with a rope. 

 A second line was attached to the stopper in such a way that pulling the 

 line removed the stopper, thereby permitting the previously sterilized 

 bottle to fill with water. When the tension on the line is released, the 

 stopper drops back into position. 



Several modifications of this type of apparatus for removing the stop- 

 per from a water bottle have been devised. Heydenreich (1899) at- 

 tached the operating string in a different way. Esmarch's bottle for col- 

 lecting samples with a rope and wire line is described by Eyre (1930). 



ZiLLiG (1929) avoided the use of the troublesome second string, which 

 has a tendency to become entangled with the supporting rope, by a mes- 

 senger arrangement for activating the removal of the stopper. The rope 

 was attached to both the bottle and the stopper in such a way that the 

 messenger releases the rope from the bottle so that the bottle is suspended 

 by the stopper which pulls the stopper from the bottle. A string connect- 

 ing the stopper to the bottle provides for hauling the bottle to the surface. 



Abbott (1921) described a sampler in which a single line is connected 

 directly to the stopper. Springs hold the stopper in the bottle until a sud- 

 den jerk on the line by the operator removes the stopper long enough to 

 permit the bottle to fill with water. A simplified version of such a mech- 

 anism is described by Whipple (1927), who pictures several other types of 

 bacteriological sampling bottles which have been used by various workers. 



Although some most ingenious devices have been designed for remov- 

 ing the stopper from bottles, all such bacteriological samplers have two 

 inherent defects: They are useless at depths exceeding 5 to 40 meters 

 where the hydrostatic pressure makes it impossible to remove the stopper, 

 and the sample may be contaminated by bacteria from the outside of the 

 sampler. 



Minervini (1900) took samples through a sea cock in the boiler room 



