public Particle CreateSubstance(sSubstance substanceToRelase)
    {
        if (nextRelease <= Time.time && substanceToRelase != null)
        {
            // It is time to spawn a new particle.

            // Create the new particle object.
            Particle newParticle = ParticlePool.instance.RequestParticle(substanceToRelase);

            // Update particle parameters.
            Vector3 spawnPosition = transform.position;
            spawnPosition.z = 0f;
            newParticle.transform.position = spawnPosition;
            newParticle.ChangeSubstanceState(substanceToRelase);
            newParticle.rb.AddForce(transform.right * relaseForce);

            // Set the timer.
            nextRelease = Time.time + releaseInterval;

            return(newParticle);
        }
        else
        {
            return(null);
        }
    }