I'm no "borax chemist" myself, but as an analytical chemist, you can be exposed to a lot of different analytical techniques that are sometimes forgotten in the modern world of chemistry. Nowadays, to measure boron content, an ICP (Inductively Coupled Plasma atomic absorbtion spectrophotometer) or even an ICP-MS (one with a mass selective spectrometer attached) would be used. 50 to 20 years ago, an AA (atomic absorption spectrophotometer) would have been used. The titration with glycerine was used from about 100 years ago until labs could afford AA's in the 50s and 60s.