Experiments with Humogen. 3 



On calling Mr. Machen's attention to this circumstance he stated that, 

 in his opinion, some inhibiting factor was present which at the time it was 

 not possible to explain. Subsequently Professor Bottomley informed me 

 he had found that the Humogen manufactured at Manchester was proving 

 unsatisfactory, apparently owing to some toxic action being produced during 

 the process, but that by adding a certain ingredient he believed this action 

 could be neutralised. At his urgent request therefore I agreed on August 22 

 to commence an entirely new series of pot experiments, including trials with 

 Manchester-manufactured Humogen treated with the necessary corrective. 



For these later tests (see Series II, pages 9 to 12) Mustard, Italian Rye 

 Grass, and Dwarf French Beans were grown, as the season was too far advanced 

 to hope for satisfactory results with the same subjects as used in Series I. 

 From the table printed on page 9 it will be seen that the experiments 

 constituting Series II were even more comprehensive in character than those 

 in Series I, and it was therefore the more disappointing that in the later 

 trials no greater success attended the use of Humogen as manufactured 

 at Manchester, although subjected to the special treatment referred to, than 

 in Series I. On the other hand, certain sections of Series II which were 

 dressed with Humogen prepared at Professor Bottomley's laboratory at 

 Greenford, gave far better results than the Manchester Humogen, and were 

 second only in merit to those dressed with a complete fertiliser. 



So far as the results of these tests show, it would appear that however 

 satisfactory Humogen may be when prepared in the laboratory, some difficulty 

 as yet exists in manufacturing this fertiliser efficiently on a commercial scale. 

 The question also arises whether, when standardised, it can be placed on the 

 market in a sufficiently concentrated form and at a price low enough to bring 

 it within the reach of large users of fertilisers. It may not be without interest 

 to mention here that the reports of outdoor experiments recently published by 

 the West of Scotland Agricultural Society, the Wisley Horticultural Research 

 Station, and others, indicate results which are almost entirely unfavourable 

 to the employment of Humogen, as then supplied, as an equivalent for 

 farmyard manure. 



Since the above notes were written, I have had the opportunity of 

 reading Dr. Russell's report of the Humogen experiments carried out under 

 his superintendence at Rothamsted during the summer of 1916. I regret to 

 see that only negative results (which appeared probable when, by Dr. Russell's 

 courtesy, I inspected the trials) were obtained. These, however, confirm my 

 own conclusions. 



