October 3, 1895] 



NATURE 



545 



(b) Experiments with Liquids and Solutions. 



I jjive only the results obtaincil with alcohol and alcoholic 

 solutions. In other liquids, such as ether and amyl alcohol, the 

 liquids had gradually evaporated, so that the exact period of their 

 action could not be ascertained, and the seeds, covered with a 

 moist oily varnish, had lost all vitality. Lucerne seeds kept in 

 chloroform for i6 years and 4 months, were completely lifeless. 

 In all the recorded experiments the seeds were completely im- 

 mersed in a relatively large volume of liquid. 



Strong Alcohol. — From March 26, 1878, to August 6, 1894, 

 or 16 years, 4 months, and 13 days. The alcohol was originally 

 absolute, but in contact with the seeds, and during so many 

 years must have absorbed a small proportion of water. Before 

 being sown, the lucerne seeds were carefully air-dried on a 

 filter for 12 hours. Out of 60 seeds sown, 40 germinated, or 

 66 6 per cent. 



Concentrated Alcoholic Solution of Corrosive Sublimate. — The 

 alcoholic solution was originally prepared with alcohol nearly 

 absolute, and saturated with mercuric chloride. From May 23, 

 1878, to August 17, 1S94, or 16 years, 2 months, and 25 days. 

 On taking the seed from the mercuric solution, they w-ere very 

 carefully washed w ith alcohol at 97 per cent, until every trace of 

 the mercuric compound was washed away. The seeds were 

 dried at the ordinary temperature, and then sown. Out of 79 

 lucerne seeds, 16 germinated, or 20"2 per cent. 



Alcoholic Solution of Sulphur Dio.xide. — From Xovember 10, 

 1878, to August 24, 1894, or 15 years, 9 months, >ind 14 days. 

 Originally the alcohol was of 93 per cent, strength ; the solution 

 preserved a suffocating odour of sulphurous acid. The lucerne 

 seeds were mixed with minute sulphur crj-stals ; the seeds were 

 well washed with strong alcohol, rlried and sown. Out of 645 

 lucerne seeds, one alone germinated, or 015 per cent. 



Alcoholic Solution of Sulphuretted Hydrogen. — From Novem- 

 ber 10, 1878, to September 4, 1894, or 15 years, 9 months, and 

 15 days. The alcohol, originally 93 per cent, strength, had 

 been repeatedly saturated with sulphuretted hydrogen gas. The 

 liquid emitted a marked mercaptanic smell. Sulphur crystals 

 were formed, and sedimented with the lucerne seeds. The 

 latter were washed with 97 per cent, alcohol, and then air- 

 dried. Out of 583 seeds, 41 germinated, or 7^03 per cent. 



Alcoholic Solution of Nitric O.ride. — From November 10, 

 1878, to September 4, 1894, a period equal to that of the last 

 described experiment. The alcohol, 93 per cent, strength, had 

 been repeatedly saturated with NO. Before sowing, the seeds 

 were washed with alcohol and dried. Out of 288 seeds, 12 

 germinated, or 4'l6 per cent. 



Alcoholic Solution of Phenol. — The lucerne seeds preser\'ed in 

 the solution for over 15 years, showed no .signs of vitality. In 

 washing the seeds, ]>revious to sowing, with alcohol, they could 

 not be completely purified from the phenol. 



Many of the germinating lucerne plants developed from the 

 seeds used m these experiments, were transplanted from the 

 germinator into flower-pots. The plants grew well, and 

 have flowered and seeded normally. 



At the beginning of these experiments, in 1877 and 1878, I 

 was not aware of the noxious action of even small proportions 

 of moisture. It is probable that if in all these experiments 

 special care had been taken at the beginning to exclude as much 

 as possible moisture, both from the seeds and from the gases or 

 liquids, a much larger proportion of seeds would have retained 

 their vitality. The ditiiculty of preserving the vitality of large 

 seeds must be chiefly caused, in all probability, by the difficulty 

 of thoroughly drying them. 



These experiments are of interest in showing that seeds may 

 retain their vitality in conditions when all respiratory exchange 

 is completely prevented for a long series of years. They fully 

 confirm the results of the late d. J. Romanes, who proved that 

 seeds may preserve their vitality for 1 5 months when kept jh 

 vacuo, or when transferred from the vacuum tubes to other tubes, 

 charged with sundry gases or vapours.' 



My experiments encourage, moreover, the suspicion that 

 latent vitality may last indefinitely when sufficient care is taken 

 to prevent all exchange with the surrounding medium. There 

 is no reason for denying the possibility of the retention of 

 vitality in seeds preserved during many centuries, such a-s the 

 mummy-wheat, and seeds front I'ompei and Herculaneum, i>ro- 

 yided that these seeds have been preserved from the beginning 

 in conditions unfavourable to chemical change. The original 



* Nature, December 7, 1893, p. 140. 

 NO. 1353, VOL. 52] 



dryness of the seeds, and their preservation from soil moisture or 

 moist air, must be the very first conditions for a latent secular 

 vitality. 



In experimenting with seeds from I'ompei and Herculaneum, 

 I have not as yet been able to find among them any living grain. 

 The greater part of these seeds are too much carbonised and 

 changed to permit the entertaining of much hope as to their 

 possible vitality. Especially among the seeds of Pompei, the 

 carbonisation must have been caused by the slow action of 

 moisture, which would speedily destroy all life in the seeds. 

 .•\mong the Pompeian wheat the destruction of organic matter 

 has been so great as to leave in the seed, in its present con- 

 dition, a proportion of ash as high, in some cases, as 4'2 per 

 cent., and even 8-4 per cent. 



On the other hand, some of these seeds, as those found in the 

 granaries of the Casa delV Argo,s.\. Herculaneum, in 1828, .seem 

 to have been in conditions favourable to a prolonged preservation 

 of latent vitality ; the millet seeds, especially, were found un- 

 change<l in outer aspect. Unfortunately, no test was made at 

 the time of their discover)', and since then the action of moist 

 air, and exposure to changes of temperature and to light, must 

 have impaired fatally any remnant of \-itality still lurking 

 amongst the seeds. 



All researches on latent life are of great interest in ascertaining 

 the nature of living matter. The present researches have estab- 

 lished that, for some seeds at least, respiration, or exchange with 

 the surrounding medium, is not necessary for the preservation of 

 germ-life. It is a common notion that life, or capacity for life, 

 is always connected with continuous chemical and physical 

 change. The very existence of li\-ing matter is supposed to imply 

 change. There is now reason for believing that living matter 

 may exist, in a completely passive state, without any chemical 

 change whatever, and may therefore maintain its special pro- 

 perties for an indefinite time, as is the case with mineral and all 

 lifeless matter. Chemical change in living matter means active 

 life, the wear and tear of which necessarily leads to death. 

 Latent life, when completely passive, in a chemical sense, ought 

 to be life without death. 



It may be finally remarked that the proof of the resistance of 

 seeds to vacuum, of the non-necessity of a respiratory exchange 

 with outer air, together with the proof of the resistance in some 

 seeds to very low temperatures, are facts encouraging the belief 

 that the origin of life on our globe may be due to the introduc- 

 tion of germs that have travelled, embedded in aerolites, from 

 other planets where life is older than upon the earth. 



Italo Cill-.I.IOl.I. 



Kegia Scuola Superiore d'Agricoltura, 

 Portici, near Naples. 



To Friends and Fellow Workers in Quaternions. 



Since the publication of Hamilton's " Elements of 

 Quaternions," in which the great mathematician developed 

 his new calculus with admirable skill and clearness, more than 

 thirty years have pa.ssed away, without it finding the adequate 

 recognition which it so highly deserves. The circumstance is 

 still the more deplorable as the calculus has since been fiirther 

 developed by Prof. Tait and others. 



There is, in truth, no question as to the importance of the use ot 

 vectorial quantities in physics, but on account of their apparently 

 preponderating im[)ortance, various physicists have been led to 

 invent new forms of vector-theory excluding the idea of 

 quaternions. But, as far as we see, they are founded on defini- 

 tions which are established by quaternions, and are systems of 

 notation rather than logical developments of a mathematical idea. 



On the other hand, many who are prejudiced against the 

 calculus of quaternions maintain the opinion that it is hard to 

 understand, and that it contains a great deal which is 

 useless in addition to things immediately applicable. To the 

 latter charge there need lie no answer, since all forms of 

 mathematics are exactly alike in this respect, and since in the 

 very combination of the pure and the applied lies the potentiality 

 of further development. In regard lu the former objection, 

 quaternionists need only say that if the objectors approach the 

 calculus of quaternions with proper care and meekness, they 

 will ere long .assuredly rejoice in having at their disirosal an 

 instrument of research mightier far than they had the slightest 

 notion of so long as they were in the domain of cartesian 

 coordinates. Certainly it would be a blessing to science if they 

 could accept these assertions, and their endeavours would find a 



