deletions | additions       diff --git a/A_bottle_of_the_substance__.tex b/A_bottle_of_the_substance__.tex  index 000ff61..4e3413e 100644  --- a/A_bottle_of_the_substance__.tex  +++ b/A_bottle_of_the_substance__.tex 
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A bottle of the substance on which NMR was being performed, which was $H_{2}O$ in our experiment, could be inserted into the center of the solenoid (as shown in Fig.(\textbf{whatever})). (Fig. \ref{fig:coils}).  The parts of the apparatus which were key to performing the NMR are the solenoid, Helmholtz coils, and gradient coils, the magnetic field of which could all be varied separately, as well as a bandpass filter, all of which are discussed below. The solenoid, with a coil constant of 15mT/A, was used to apply a magnetic field to polarize the water. The magnetic field of the solenoid could be varied used a variable current input. The field of the Helmholtz coils, which effectively artificially increased or decreased the Earth's magnetic field applied in the sample, was adjusted using a separate variable current input. The gradient coils changed the gradient of the magnetic field in the x, y, and z directions, but the gradient was not varied over the course of this experiment.