TRANSACTIONS OF SECTION K. 791 
winter meeting of the German Agricultural Society in February of this year,' 
puts the cost of electric nitrate, as compared with Chili nitrate, in the proportion 
of 24 to 39, which is in close agreement with Sir William Crookes’s estimate. 
Lepel points out that the material obtained, neutralised by some alkali, consists of 
a mixture of nitrate and nitrite. When used in pot-culture experiments it 
has given results closely agreeing with those furnished by Chili nitrate. 
Good progress would also appear to have been made in another direction in 
the commercial fixation of atmospheric nitrogen, and a short account of the results 
was communicated by Professor Gerlach, of Posen, to the meeting of the German 
Agricultural Society already referred to, and is published in the same issue of the 
‘ Mittheilungen.’ 
When air which has been freed of oxygen is conducted through finely dis- 
integrated calcium carbide at a high temperature, one atom of carbon is displaced 
by two atoms of nitrogen, and calcium cyanamide (CaCN,) is formed. This 
substance is also produced when a mixture of lime or chalk and charcoal is heated 
to a temperature of 2,000 deg. C. in a current of air.» When pure, this substance 
holds 35 per cent. of nitrogen, but in its crude commercial form it contains only 
about 20 per cent. Treated with acids, calcium cyanamide is changed into 
dicyandiamide, a substance holding nearly 67 per cent. of nitrogen, but directly 
poisonous to plants. Or, if heated in superheated steam, calcium cyanamide parts 
pe all its nitrogen as ammonia, which, of course, is easily brought into a portable 
orm. 
But experiments conducted at Posen and Darmstadt during the past three 
years, both in pots and in the open field, have shown that calcium cyanamide 
itself is a useful nitrogenous manure, field experiments giving results about 
20 per cent. below those obtained by the use of an equal amount of nitrogen in the 
form of sulphate of ammonia. In prepared soil in pots the results fully surpassed 
those obtained both with nitrate of soda and sulphate of ammonia, the less 
satisfactory yields obtained in the field being perhaps due to the organic acids 
inducing the formation of a certain amount of the poisonous dicyandiamide. 
So far as one may judge from the information available, it would appear that 
agriculture will not have long to wait till it is placed in the possession of new 
supplies of that most powerful agent of production, nitrogen, and Sir William 
ant will see the fulfilment of his prediction that ‘the future can take care of 
itself, 
Nitragin. 
A few years ago much interest was excited in this and other countries by the 
announcement that the scientific discoveries of Hellriegel and Wilfarth had received 
commercial application, and that the organisms of the nodules of the roots of 
Leguminose could be purchased in a form convenient for artificial inoculation. 
The specific cultures placed upon the market were largely tested practically and 
experimentally, but the results were such as to convince even the patentees, Nobbe 
and Hiltner, that the problem which promised so much for agriculture had not 
been satisfactorily solved. Since that time, however, investigators have not been 
idle, and the present position of the subject is to be found in a recent Report by 
Hiltner and Stérmer.® 
It was early recognised that the organisms (bacteria) which inhabited the root 
nodules of the various species of Leguminose were not all alike, and that, in fact, 
they showed marked physiological if not morphological distinctions. Any par- 
ticular species of leguminous plant is found to resist more or less successfully 
1 Dr. von Lepel, ‘Neuere Versuche zur Nutzbarmachung des atmosphirischen 
pee etols durch Elektrische Flammenbogen,’ Mitteil. d. Deut. Land. Gesell., 1904, 
Stiick 8. , 
2 Bull, Zmp. Inst. June 30, 1904. 
3 ¢ Bericht tiber neue Untersuchungen tiber die Wurzelkndllchen der Leguminosen 
und deren Erreger,’ Arbeiten aus der Biol. Abteil. fiir Land+ und Forstivirtschaft am 
XK, Gesundheitsamte, Band iii. Heft 3. 
