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diff --git a/kamon-core/src/test/scala/kamon/metric/instrument/HistogramSpec.scala b/kamon-core/src/test/scala/kamon/metric/instrument/HistogramSpec.scala
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+/*
+ * =========================================================================================
+ * Copyright © 2013 the kamon project <http://kamon.io/>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the
+ * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific language governing permissions
+ * and limitations under the License.
+ * =========================================================================================
+ */
+
+package kamon.metric.instrument
+
+import java.nio.LongBuffer
+
+import com.typesafe.config.ConfigFactory
+import kamon.metric.CollectionContext
+import org.scalatest.{ Matchers, WordSpec }
+
+import scala.util.Random
+
+class HistogramSpec extends WordSpec with Matchers {
+
+  val histogramConfig = ConfigFactory.parseString(
+    """
+      |
+      |highest-trackable-value = 100000
+      |significant-value-digits = 2
+      |
+    """.stripMargin)
+
+  "a Histogram" should {
+    "allow record values within the configured range" in new HistogramFixture {
+      histogram.record(1000)
+      histogram.record(5000, count = 100)
+      histogram.record(10000)
+    }
+
+    "fail when recording values higher than the highest trackable value" in new HistogramFixture {
+      intercept[IndexOutOfBoundsException] {
+        histogram.record(1000000)
+      }
+    }
+
+    "reset all recorded levels to zero after a snapshot collection" in new HistogramFixture {
+      histogram.record(100)
+      histogram.record(200)
+      histogram.record(300)
+
+      takeSnapshot().numberOfMeasurements should be(3)
+      takeSnapshot().numberOfMeasurements should be(0)
+    }
+
+    "produce a snapshot" which {
+      "supports min, max and numberOfMeasurements operations" in new HistogramFixture {
+        histogram.record(100)
+        histogram.record(200, count = 200)
+        histogram.record(300)
+        histogram.record(900)
+
+        val snapshot = takeSnapshot()
+
+        snapshot.min should equal(100L +- 1L)
+        snapshot.max should equal(900L +- 9L)
+        snapshot.numberOfMeasurements should be(203)
+      }
+
+      "can be merged with another snapshot" in new MultipleHistogramFixture {
+        val random = new Random(System.nanoTime())
+
+        for (repetitions ← 1 to 1000) {
+          // Put some values on A and Control
+          for (_ ← 1 to 1000) {
+            val newRecording = random.nextInt(100000)
+            controlHistogram.record(newRecording)
+            histogramA.record(newRecording)
+          }
+
+          // Put some values on B and Control
+          for (_ ← 1 to 2000) {
+            val newRecording = random.nextInt(100000)
+            controlHistogram.record(newRecording)
+            histogramB.record(newRecording)
+          }
+
+          val controlSnapshot = takeSnapshotFrom(controlHistogram)
+          val histogramASnapshot = takeSnapshotFrom(histogramA)
+          val histogramBSnapshot = takeSnapshotFrom(histogramB)
+
+          assertEquals(controlSnapshot, histogramASnapshot.merge(histogramBSnapshot, collectionContext))
+          assertEquals(controlSnapshot, histogramBSnapshot.merge(histogramASnapshot, collectionContext))
+        }
+      }
+    }
+  }
+
+  trait HistogramFixture {
+    val collectionContext = new CollectionContext {
+      val buffer: LongBuffer = LongBuffer.allocate(10000)
+    }
+
+    val histogram = Histogram.fromConfig(histogramConfig)
+
+    def takeSnapshot(): Histogram.Snapshot = histogram.collect(collectionContext)
+  }
+
+  trait MultipleHistogramFixture {
+    val collectionContext = new CollectionContext {
+      val buffer: LongBuffer = LongBuffer.allocate(10000)
+    }
+
+    val controlHistogram = Histogram.fromConfig(histogramConfig)
+    val histogramA = Histogram.fromConfig(histogramConfig)
+    val histogramB = Histogram.fromConfig(histogramConfig)
+
+    def takeSnapshotFrom(histogram: Histogram): Histogram.Snapshot = histogram.collect(collectionContext)
+
+    def assertEquals(left: Histogram.Snapshot, right: Histogram.Snapshot): Unit = {
+      left.numberOfMeasurements should equal(right.numberOfMeasurements)
+      left.min should equal(right.min)
+      left.max should equal(right.max)
+      left.recordsIterator.toStream should contain theSameElementsAs (right.recordsIterator.toStream)
+    }
+  }
+}