“…These translucent rings are always compared with the corresponding translucent standard scale prepared with hard paraffin wax. 88 Hashmi and co-workers described the determination of a number of organic substances, e.g., amino-acid~~~ and vitamins,70 with the "Nichrome-wire ring chamber,'' using a somewhat different approach ("sensitivity scale") that had previously been discussed in principle by Wenger et al ("extinction method").71…”