( 109) 



This agreement makes it already very probable tiiat the Röntgen 

 rays also consist in transversal vibrations; these experiments however 

 yield a firmer proof for this thesis. Tf namely we accept the suppo- 

 sition of Barkla as to the way of generation of secondary rays in 

 bodies with a small atomic weight, then it may easily be shown, 

 that the supposition of a /o/i^iVz^c/ma/ vibration of the primary Röntgen 

 rays would, in the experiment discussed here, lead to a maximum 

 action of the tertiary rays in a vertical plane and not in an hori- 

 zontal plane, as was the case. 



Groningen, Physical Laboratory of the University. 



Chemistry. — "Triformin {Gli/ceri/l irifonnate)". By Prof. P. van 



ROMBURGH. 



Many years ago I was engaged in studying the action of oxalic 

 acid on glycerol') and then showed that in the preparation of formic 

 acid by Lorin's method diformin is produced as an intermediate product. 



Even then I made efforts to prepare triformin, which seemed to 

 me of some importance as it is the most simple representative of the 

 fats, by heating the diformin with anhydrous oxalic acid, but I was 

 not successful at the time. Afterwards Lorin ') repeated these last 

 experiments with very large quantities of anhydrous oxalic acid and 

 stated that the formic acid content finally rises to 75°/o, but he does 

 not mention any successful efforts to isolate the triformin. 



Since my first investigations, I have not ceased efforts to gain my 

 object. I confirmed Lorin's statements that on using very large 

 quantities of anhydrous oxalic acid, the formic acid content of the 

 residue may be increased and I thought that the desired product 

 might be obtained after all by a prolonged action. 



Repeated efforts have not, however, had the desired result, although 

 a formin with a high formic acid content was produced from which 

 could be obtained, by fractional distillation in vacuo, a triformin still 

 containing a few percent of the di-compound. 



I will only mention a few series of experiments which I 

 made at Buitenzorg, first with Dr. Nanninga and afterwards w4th 

 Dr. Long. In the first, a product was obtained which had a sp.gr. 1.309 

 at 25", and gave on titration 76.67o of formic acid, whilst pure 

 triformin requires 78.47o- The deficiency points to the presence of 

 fully 107o of diformin in the product obtained. 



1) Gompt. Rend. 93 (1881) 847. 



2) Gompt. Rend. 100 (1885) 282. 



