Most spices, unfortunately, are relatively light-weight. This meant that the ship could be unstable at sea because she lacked the proper ballast to keep her upright in a good blow. Most captains would take on other cargo in addition to the spices, even if it meant shipping rocks in the bilges in order to get the proper weight for sailing.
Along with nutmeg, cinnamon, and ginger, the shipments of this time were generally of pepper, which is still the single largest spice consumed to this day. In one ship's log, it was noted that a member of the crew had passed away during the return voyage. His wish was to be buried at home, and for some reason that wish was granted. The body was packed away in pepper as a preservative. The doctor's assessment upon seeing the body when the ship arrived in Salem was to comment at how well preserved the remains were. In fact, mummies from ancient Egypt are found with peppercorns stuffed in cavities to aid the preservation.
Salem fortunes were built on spices imported primarily from Sumatra. These were called the spice islands for many, many years. Salem is home to the Peabody Essex Museum, which was originally the East India Museum and contained some of the treasures from afar as brought back by the ship captains. Although the custom house was right across the street from the piers, smuggling was rampant. Downtown Salem is full of underground tunnels, most of which were used for smuggling as much as anything else. Some stories say that the East India Museum was created when the ships would come back into port with goods that were not quite destined for the open market. If the goods were not discovered, they went on to become private property. If they were discovered, they went into the museum.