1795

Mendel’s experiments were to show that the contrasted unit-characters gave plants with these contrasted characters inthe ratio 1 : 2 : 1, a frequency result. Mendel’s theory-gametic segregation-was that this was a frequency resultdue to the combination of the pollen grains and egg cellsand thus like (a + b) 2 we get 1:2:1. For reasons I neednot state here I have suggested that the determinants of theunit-characters are segregated according to the law of fre-

quency, and that this happens in the zygote. This was

suggested to me by the changes in the free-martin, a sterilebull usually co-twin with a potent bull, both derived fromone zygote, where in the zygote the unit-character (epoophoronand prostatic utricle) is segregated into the sterile animal.The question of gametic combination versus zygotic segrega-tion is the most important in Mendelism. Everythingdepends on it-it is not a ’’ slight criticism of Mendelism "-and that is my main reason for troubling you with thisletter. I am, Sir, yours faithfully,Edinburgh, Dec. 5th, 1910. D. BERRY HART.

* The author’s complaint is just. The attribution to himin the review of the statement that changes in the zygotemake up the necessary complement, &c.," was an error.

It should, of course, have been explicitly stated that thezygotic segregation specially insisted on by the authoris subsequent to the union of gametes which makes upthis necessary complement. Our reviewer writes regrettingthe error, adding : " But that it was not due to a

misunderstanding or purposive misrepresentation of the

author’s special theory is clear from the subsequentquotations from pp. 94, 95 of the book. The sentence

quoted by the author as the reviewer’s definition’ of

Mendelian results was not a definition of anything,but merely a condensed indication of the line of argu-ment employed to lead up to the author’s theory of

’ zygotic segregation’ or division of the zygote into a

’propagative and a somatic part,’ which he opposes to

the hypothesis of gametic segregation as set forth byMendel. The reviewer’s error, even if it had been made in

ignorance, does not touch the main criticism, which is, in-effect, that the intrinsic theory of variation, &c., is but a

hypothetical amendment, or an attempt at a reconciliation,of certain existing hypotheses rather than a comprehensivehandling of the subject as a whole."-ED. L.

D. BERRY HART.

THE INTRAVENOUS INJECTION OF

SALVARSAN, OR " 606."To the Editor of THE LANCET.

SIR,-Salvarsan, or " 606," to give Professor Ehrlich’s saltits more popular name, may be given by intramuscular or byintravenous injection. When administered intramuscularlythere is for some few days after undoubtedly a very consider-able amount of pain, which may be controlled by morphia ; ;but morphia, whatever 11 606 " may turn out to be, is

certainly no cure for syphilis, and the patient is betterwithout any further addition from the Pharmacopœia of apoisonous nature, saturated, as he already is, with the

spirochæta and the salvarsan. On the other hand, when theinjection is made directly into the vein, there is no paincaused beyond the prick of the needle, either at the time ofthe operation or afterwards.This point alone is a very definite reason for a preference

in favour of the intravenous method, and a reason to whichthe patient himself would be the first to subscribe. Beyondthis, however, I think I can, reasoning by analogy, give goodcause to show why it should also have the preference overintramuscular injection on account of its probable greateraction and efficiency when introduced intravenously. Now,during the years 1896-1897, when I published a paper on theTechnique of the Treatment of Syphilis by Intravenous

Injection of Mercury, I had certain primary and secondarycases in private undergoing six-week courses of this treatmentthree times a year over two years, with, at the time, highlysatisfactory results. These cases being in private enabled me,when Wassermann perfected his reaction, to communicate

1 Brit. Med. Jour., April 4th, 1897.

with them and to obtain their blood for the purpose of find-

ing if they were positive or negative to the disease.Although, from the point of view of statistics, the numbers

are not numerous enough to deduce any absolute conclusion,yet the way their bloods have been returned as negative,without exception, is highly suggestive of the efficacy of thattreatment by mercury directly into the blood-stream. Thereason for this efficacy is, I take it, that the medicamentis directly introduced into the very atmosphere of the body,into the blood-stream itself, and so has the sameadvantages as the spirochæta which has taken the sameroad to reach the most out-of-the-way cells and tissues,where, taking part in their metabolism, the "war" withthe poison is carried on simultaneously and immediatelyall over the body. Again, owing to the rapid excretion ofthe mercury when given in this way, the injections beingrepeated three times a week, the specific poison receiveshard and direct blows delivered against it with a verytelling frequency.Now if this reasoning is correct for Hg, how much more

important is it to make the blow delivered by salvarsan a" knock-out " one ; for here we are aiming at attaining ourobject of the total destruction of the spirochæta by meansof one single injection, and look upon the necessity ofrepeating the operation as a comparative failure ; for, what-ever Hg may do, there is a probability that the complicatedmolecule we name salvarsan or "606" induces the bloodto give rise to an antigen, because if we fail with thefirst dose to annihilate, any second dose must be greater inquantity to enable us to produce the desired result. In

conclusion, therefore, if we have in salvarsan a bulletwhich will kill the enemy, I hope I have given some goodreason for showing how we can make that bullet a dum-dum.

I am, Sir, yours faithfully,Sackville-street, W. JAMES B. BYLES.JAMES B. BYLES.

THE OWNERSHIP OF PRESCRIPTIONS.To the Editor of THE LANCET.

SIR,—I am glad to learn from Dr. Lucas Benham’s letter,which appears in this week’s issue of THE LANCET, that myarticle on the above subject has excited interest, and hasbeen on the whole approved so far afield, and particularlythat Dr. Benham makes it a practice to indicate on the faceof every prescription he writes the maximum time for whichit should be used. This excellent practice deserves, how-ever, to be supported by better arguments than those whichcan be deduced from the analogy-in my opinion a false one-of a cheque. There is no parity in the conditions. A

cheque is an order addressed to a banker, requiring him topay a sum of money to a certain person, or to the bearerof the cheque, out of funds previously deposited with himby the writer of the cheque. A prescription is a formulagiven by a physician to his patient, who can have it

compounded by any competent person he chooses to

employ. The banker is an agent of the maker of the

cheque ; the dispenser is an independent contractor whodeals only with the holder of the prescription. Theseare the conditions generally obtaining in this country;they may perhaps be modified in South Australia.

I am, Sir, yours faithfully,Middle Temple, Dec. 12th, 1910. H. WIPPELL GADD.H. WIPPELL GADD.

THE RESULTS OF BRONCHIALOBSTRUCTION.

To the -Editor of THE LANCET.

SIR,—I have just read Dr. Newton Pitt’s admirableBradshaw Lecture with great interest, for it has taught mesomething that I did not know before, although that some-thing has been under my observation for many years and Ihave missed it. I refer to the fact that a partial compressionof a bronchus is capable of producing an over-distendedlung. On finishing Dr. Pitt’s lecture I immediately lookedup my skiagrams of aneurysm, and found that three outof seven show the condition distinctly. I have not yethad time to go through my hospital cases, but intend doingso on the first opportunity. As Dr. Pitt has kindly mentionedmy name in connexion with two of the published skiagramsI feel that a word about them will not be out of place. Iremember the cases well. as they cccurred in Victoria ParkHospital. The skiagram shown in Fig. 7 was actually mistakenfor a pneumothorax, but that was as long ago as 1902 ; since