#include <Wire.h>

void setup() {
  Wire.begin();        // join i2c bus (address optional for master)
 }

void loop() {
  Wire.requestFrom(8, 1);    // request 6 bytes from slave device #8

  if (Wire.available()) { // slave may send less than requested
    char c = Wire.read(); // receive a byte as character
    delay(1);
    Wire.beginTransmission(9); // transmit to device #9
    Wire.write(c);              // sends one byte
    Wire.endTransmission();    // stop transmitting
  }
  
  delay(10);
}