Kipps Apparatus made of polyethylene has three main portions. The top portion is fitted with a thistle funnel and a bulb structure through which dilute acid can be poured which reacts with metal sulphide in the base of the apparatus. The H2S gas then evolved collects in the middle dome from where it can be released through a leak-proof stopcock fitted with a self-lubricating PTEE plug. The base is provided with a residual outlet fitted with a cap for easy cleaning.